* input/regression/bar-number.ly: remove unnecessary old-relative

[lilypond.git] / Documentation / user / refman.itely

@c Note: -*-texinfo-*-
@c
@c A menu is needed before every deeper *section nesting of @node's; run
@c     M-x texinfo-all-menus-update
@c to automagically fill in these menus before saving changes
@c
@c FIXME: singular vs. plural:  Beams/Beam


@node Notation manual
@chapter Notation manual

@menu
* Note entry::                  
* Easier music entry::          
* Staff notation::              
* Polyphony::                   
* Beaming::                     
* Accidentals::                 
* Expressive marks::            
* Articulations::               
* Fingering instructions::      
* Repeats::                     
* Rhythmic music::              
* Piano music::                 
* Vocal music::                 
* Tablatures::                  
* Chord names::                 
* Orchestral music::            
* Ancient notation ::           
* Contemporary notation::       
* Tuning output::               
* Global layout::               
* Sound::                       
@end menu

@c FIXME: Note entry vs Music entry at top level menu is confusing.

@node Note entry
@section Note entry
@cindex Note entry

This chapter describes all the different types of notation supported
by LilyPond. It is intended as a reference for users that are already
somewhat familiar with using LilyPond.


@menu
* Notes::                       
* Pitches::                     
* Chromatic alterations::       
* Chords::                      
* Rests::                       
* Skips::                       
* Durations::                   
* Stems::                       
* Ties::                        
* Tuplets::                     
* Easy Notation note heads ::   
@end menu


@node Notes
@subsection Notes


A note is printed by specifying its pitch and then its duration:
@footnote{Notes constitute the most basic elements of LilyPond input,
but they do not form valid input on their own without a @code{\score}
block.  However, for the sake of brevity and simplicity we will
generally omit @code{\score} blocks and @code{\paper} declarations in
this manual.}

@lilypond[fragment,verbatim]
  cis'4 d'8 e'16 c'16
@end lilypond


@node Pitches
@subsection Pitches

@cindex Pitch names
@cindex Note specification
@cindex pitches
@cindex entering notes

The most common syntax for pitch entry is used in @code{\chords} and
@code{\notes} mode.  In Note and Chord mode, pitches may be designated
by names.  The notes are specified by the letters @code{a} through
@code{g}, while the octave is formed with notes ranging from @code{c}
to @code{b}.  The pitch @code{c} is an octave below middle C and the
letters span the octave above that C:

@lilypond[fragment,verbatim]
\clef bass
  a,4 b, c d e f g a b c' d' e' \clef treble f' g' a' b' c''
@end lilypond

@cindex note names, Dutch

A sharp is formed by adding @code{-is} to the end of a pitch name and
a flat is formed by adding @code{-es}.  Double sharps and double flats
are obtained by adding @code{-isis} or @code{-eses}.  These
names are the Dutch note names.  In Dutch, @code{aes} is contracted to
@code{as} in Dutch, but both forms are accepted. Similarly, both
@code{es} and @code{ees} are accepted.

There are predefined sets of note names for various other languages.
To use them,  include the language specific init file.  For
example: @code{\include "english.ly"}.  The available language files
and the note names they define are:

@anchor{note name}
@anchor{note names}
@example 
                        Note Names               sharp       flat
nederlands.ly  c   d   e   f   g   a   bes b   -is         -es
english.ly     c   d   e   f   g   a   bf  b   -s/-sharp   -f/-flat
deutsch.ly     c   d   e   f   g   a   b   h   -is         -es
norsk.ly       c   d   e   f   g   a   b   h   -iss/-is    -ess/-es
svenska.ly     c   d   e   f   g   a   b   h   -iss        -ess
italiano.ly    do  re  mi  fa  sol la  sib si  -d          -b
catalan.ly     do  re  mi  fa  sol la  sib si  -d/-s       -b 
espanol.ly     do  re  mi  fa  sol la  sib si  -s          -b 

@end example 

@cindex @code{'}
@cindex @code{,}



The optional octave specification takes the form of a series of
single quote (`@code{'}') characters or a series of comma
(`@code{,}') characters.  Each @code{'} raises the pitch by one
octave; each @code{,} lowers the pitch by an octave:

@lilypond[fragment,verbatim,center]
  c' c'' es' g' as' gisis' ais'  
@end lilypond


There is also a verbose syntax for pitch specification:

@c TODO: junk this? 
@cindex @code{\pitch}
@example
  \pitch @var{scmpitch}
@end example


where @var{scmpitch} is a Scheme object of the @code{Pitch} type.

@refcommands

Notes can be hidden and unhidden with the following commands:

@cindex @code{\hideNotes}
@code{\hideNotes}, 
@cindex @code{\unHideNotes}
@code{\unHideNotes}.


@seealso

@noindent
@internalsref{NoteEvent}, and @internalsref{NoteHead}.

@node Chromatic alterations
@subsection Chromatic alterations

Normally accidentals are printed automatically, but you may also
print them manually.  A reminder accidental
@cindex reminder accidental
@cindex @code{?}
can be forced by adding an exclamation mark @code{!}
after the pitch.  A cautionary accidental
@cindex cautionary accidental
@cindex parenthesized accidental
(an accidental within parentheses) can be obtained by adding the
question mark `@code{?}' after the pitch:

@lilypond[fragment,verbatim]
  cis' cis' cis'! cis'?
@end lilypond


The automatic production of accidentals can be tuned in many
ways. For more information, refer to @ref{Accidentals}.

@node Chords
@subsection Chords

A chord is formed by a enclosing a set of pitches in @code{<<} and
@code{>>}. A chord may be followed by  a duration, and a set of
articulations, just like simple notes.


@node  Rests
@subsection Rests
@cindex Rests




Rests are entered like notes, with the note name @code{r}:

@lilypond[singleline,verbatim]
r1 r2 r4 r8
@end lilypond

Whole bar rests, centered in middle of the bar,
must be done  with multi measure rests. They are discussed in
@ref{Multi measure rests}.


A rest's vertical position may be explicitly specified by entering a
note with the @code{\rest} keyword appended. This makes manual
formatting in polyphonic music easier.  Rest collision testing will
leave these rests alone:

@lilypond[singleline,verbatim]
a'4\rest d'4\rest
@end lilypond

@seealso

@internalsref{RestEvent}, and @internalsref{Rest}.


@c FIXME: naming.
@node Skips
@subsection Skips
@cindex Skip
@cindex Invisible rest
@cindex Space note

An invisible rest (also called a `skip') can be entered like a note
with note name `@code{s}' or with @code{\skip @var{duration}}:

@lilypond[singleline,verbatim]
a2 s4 a4 \skip 1 a4 
@end lilypond

The @code{s} syntax is only available in Note mode and Chord mode.  In
other situations, you should use the @code{\skip} command:

@lilypond[singleline,verbatim]
\score {
  \context Staff <
    { \time 4/8 \skip 2 \time 4/4 } 
    \notes\relative c'' { a2 a1 }
  >
}
@end lilypond

The skip command is merely an empty musical placeholder.  It does not
produce any output, not even transparent output.

@seealso

@internalsref{SkipEvent}.



@node Durations
@subsection Durations


@cindex duration
@cindex @code{\duration}


In Note, Chord, and Lyrics mode, durations are designated by numbers
and dots: durations are entered as their reciprocal values.  For example,
a quarter note is entered using a @code{4} (since it is a 1/4 note), while
a half note is entered using a @code{2} (since it is a 1/2 note).  For notes
longer than a whole you must use variables:

@c FIXME: what is an identifier?  I do not think it's been introduced yet.
@c and if it has, I obviously skipped that part.     - Graham

@example 
c'\breve  
c'1 c'2 c'4 c'8 c'16 c'32 c'64 c'64 
r\longa r\breve  
r1 r2 r4 r8 r16 r32 r64 r64 
@end example 

@lilypond[noindent]
\score {
  \notes \relative c'' {
    a\breve  \autoBeamOff
    a1 a2 a4 a8 a16 a32 a64 a64 
    r\longa r\breve  
    r1 r2 r4 r8 r16 r32 r64 r64 
  }
  \paper {
    \translator {
      \StaffContext
        \remove "Clef_engraver"
        \remove "Staff_symbol_engraver"
        \remove "Time_signature_engraver"
        \consists "Pitch_squash_engraver"
    }
  }
}
@end lilypond


If the duration is omitted then it is set to the previously entered
duration. The default for the first note is a quarter note.  The duration
can be followed by dots (`@code{.}') in order to obtain dotted note
lengths:
@cindex @code{.}

@lilypond[fragment,verbatim,center]
  a' b' c''8 b' a'4 a'4. b'4.. c'8.
@end lilypond
@cindex @code{r}
@cindex @code{s}

You can alter the length of duration by a fraction @var{N/M}
appending `@code{*}@var{N/M}' (or `@code{*}@var{N}' if @var{M=1}). This
will not affect the appearance of the notes or rests produced.
In the following example, the first three notes take up exactly two
beats:
@lilypond[fragment,relative 2,verbatim]
  \time 2/4
   a4*2/3 gis4*2/3 a4*2/3
   a4
@end lilypond

Durations can also be produced using the verbose syntax
@code{\duration @var{Scheme object}}:
@lilypond[verbatim,fragment]
 c'\duration #(ly:make-duration 4 1)
@end lilypond



@refcommands

Dots are normally moved up to avoid staff lines, except in polyphonic
situations. The following commands may be used to force a particular
direction manually:

@cindex @code{\dotsUp}
@code{\dotsUp}, 
@cindex @code{\dotsDown}
@code{\dotsDown}, 
@cindex @code{\dotsBoth}
@code{\dotsBoth}.

@seealso

@internalsref{Dots}, and @internalsref{DotColumn}. 

@refbugs

In dense chords, dots can overlap.

@node Stems
@subsection Stems

Whenever a note is found,  a
@internalsref{Stem} object is created automatically. For whole notes
and rests, stem objects are also created, but in those cases, the stem
is invisible.

@refcommands

@cindex @code{\stemUp}
@code{\stemUp}, 
@cindex @code{\stemDown}
@code{\stemDown}, 
@cindex @code{\stemBoth}
@code{\stemBoth}. 


@node Ties
@subsection Ties

@cindex Tie
@cindex ties
@cindex @code{~}

A tie connects two adjacent note heads of the same pitch.  The tie in
effect extends the length of a note.  Ties should not be confused with
slurs, which indicate articulation, or phrasing slurs, which indicate
musical phrasing.  A tie is entered using the tilde symbol `@code{~}':

@lilypond[fragment,verbatim,center]
  e' ~ e' <<c' e' g'>> ~ <<c' e' g'>>
@end lilypond

When a tie is applied to a chord, all note heads whose pitches match
are connected.  When no note heads match, no ties will be created.

In its meaning a tie is just a way of extending a note duration, similar
to the augmentation dot; in the following example there are two ways of 
notating exactly the same concept:
@c
@lilypond[fragment, singleline,quote]
\time 3/4 c'2. c'2 ~ c'4
@end lilypond
If you need to tie a lot of  notes over bars, it may be easier to use automatic
note splitting (See @ref{Automatic note splitting}).

@refcommands


@cindex @code{\tieUp}
@code{\tieUp}, 
@cindex @code{\tieDown}
@code{\tieDown}, 
@cindex @code{\tieBoth}
@code{\tieBoth}, 
@cindex @code{\tieDotted}
@code{\tieDotted}, 
@cindex @code{\tieSolid}
@code{\tieSolid}.

@seealso 

@internalsref{TieEvent}, @internalsref{NewTieEvent},
@internalsref{Tie}, and @ref{Automatic note splitting}.

If you want less
ties created for a chord, see @inputfileref{input/test,tie-sparse.ly}.

@refbugs

Tieing only a subset of the note heads of a pair of chords is not
supported in a simple way.  It can be achieved by moving the
tie-engraver into the @internalsref{Thread} context and turning on and
off ties per @internalsref{Thread}.

Switching staves when a tie is active, will not produce a slanted tie.

Formatting of ties is a difficult subject. The results are often not
optimal.



@node Tuplets
@subsection Tuplets

@cindex tuplets
@cindex triplets
@cindex @code{\times}

Tuplets are made out of a music expression by multiplying all durations
with a fraction:

@cindex @code{\times}
@example
  \times @var{fraction} @var{musicexpr}
@end example

The duration of @var{musicexpr} will be multiplied by the fraction. 
In the sheet music, the fraction's denominator will be printed over
the notes, optionally with a bracket.  The most common tuplet is the
triplet in which 3 notes have the length of 2, so the notes are 2/3
of their written length:

@lilypond[fragment,verbatim,center]
  g'4 \times 2/3 {c'4 c' c'} d'4 d'4
@end lilypond

The property @code{tupletSpannerDuration} specifies how long each
bracket should last.  With this, you can make lots of tuplets while
typing @code{\times} only once, saving lots of typing. In the next
example, there are two triplets shown, while @code{\times} was only
used once:

@lilypond[fragment,  relative, singleline, verbatim]
\property Voice.tupletSpannerDuration = #(ly:make-moment 1 4)
\times 2/3 { c'8 c c c c c }
@end lilypond

The format of the number is determined by the property
@code{tupletNumberFormatFunction}.  The default prints only the
denominator, but if it is set to the Scheme function
@code{fraction-tuplet-formatter}, @var{num}:@var{den} will be printed
instead.


@cindex @code{tupletNumberFormatFunction}
@cindex tuplet formatting 


@refcommands

@cindex @code{\tupletUp}
@code{\tupletUp}, 
@cindex @code{\tupletDown}
@code{\tupletDown}, 
@cindex @code{\tupletBoth}
@code{\tupletBoth}.

@seealso

@internalsref{TupletBracket}, and @internalsref{TimeScaledMusic}.

@refbugs

Nested tuplets are not formatted automatically.  In this case, outer
tuplet brackets should be moved manually.

@node Easy Notation note heads 
@subsection Easy Notation note heads

@cindex easy notation
@cindex Hal Leonard

The `easy play' note head includes a note name inside the head.  It is
used in music aimed at beginners:

@lilypond[singleline,verbatim,26pt]
\score {
  \notes { c'2 e'4 f' | g'1 }
  \paper { \translator { \EasyNotation } } 
}
@end lilypond

The @code{EasyNotation} variable overrides a @internalsref{Score} context.  
You probably will want to print it with magnification or a
large font size to make it more readable.  To print with
magnification, you must create a DVI file (with @file{ly2dvi}) and
then enlarge it with something like @file{dvips -x 2000 file.dvi}.
See the @code{dvips} documentation for more details.  To print with a
larger font, see @ref{Font Size}.


@cindex Xdvi
@cindex ghostscript

If you view the result with Xdvi, then staff lines will show through
the letters.  Printing the PostScript file obtained with ly2dvi does
produce the correct result.


@node Easier music entry
@section Easier music entry
@cindex Music entry

When entering music it is easy to introduce errors. This section deals
with tricks and features of the input language that help when entering
music, and find and correct mistakes.  Some features of the input
language ease entering music, but also have other applications. They
are not described in this section.

It is also possible to use external programs, for example GUI
interfaces, or MIDI transcription programs, to enter or edit
music. Refer to the website for more information. Finally, there are
tools make debugging easier, by linking the input file and the output
shown on screen. See @ref{Point and click} for more information.


@menu
* Relative octaves::            
* Octave check::                
* Bar check::                   
* Skipping corrected music::    
* Automatic note splitting ::   
@end menu




@node Relative octaves
@subsection Relative octaves
@cindex Relative
@cindex relative octave specification

Octaves are specified by adding @code{'} and @code{,} to pitch names.
When you copy existing music, it is easy to accidentally put a pitch
in the wrong octave and hard to find such an error. The relative
octave mode prevents these errors: a single error puts the rest of the
piece off by one octave:

@cindex @code{\relative}
@example
  \relative @var{startpitch} @var{musicexpr}
@end example

The octave of notes that appear in @var{musicexpr} are calculated as
follows: If no octave changing marks are used, the basic interval
between this and the last note is always taken to be a fourth or less
(; this distance is determined without regarding alterations: a
@code{fisis} following a @code{ceses} will be put above the
@code{ceses}).

The octave changing marks @code{'} and @code{,} can be added to raise
or lower the pitch by an extra octave.  Upon entering relative mode,
an absolute starting pitch must be specified that will act as the
predecessor of the first note of @var{musicexpr}.

Here is the relative mode shown in action:
@lilypond[fragment,singleline,verbatim,center]
  \relative c'' {
    b c d c b c bes a 
  }
@end lilypond

Octave changing marks are used for intervals greater than a fourth:
@lilypond[fragment,verbatim,center]
  \relative c'' {
    c g c f, c' a, e'' }
@end lilypond

If the preceding item is a chord, the first note of the chord is used
to determine the first note of the next chord:

@lilypond[fragment,verbatim,center]
  \relative c' {
    c <<c e g>> 
    <<c' e g>>
    <<c, e' g>>
  }
@end lilypond 
@cindex @code{\notes}

The pitch after the @code{\relative} contains a note name.  To parse
the pitch as a note name, you have to be in note mode, so there must
be a surrounding @code{\notes} keyword (which is not
shown here).

The relative conversion will not affect @code{\transpose},
@code{\chords} or @code{\relative} sections in its argument.  If you
want to use relative within transposed music, you must place an
additional @code{\relative} inside the @code{\transpose}.

@node Octave check
@subsection Octave check


Octave checks make octave errors easier to correct.
The syntax is 
@example
  \octave @var{pitch}
@end example

This checks that @var{pitch} (without octave) yields @var{pitch} (with
octave) in \relative mode. If not, a warning is printed, and the
octave is corrected, for example, the first check is passed
successfully.  The second check fails with an error message.  The
octave is adjusted so the following notes are in the correct octave
once again.
@example
   \relative c' @{
     e
     \octave a'
     \octave b'
   @}
@end example


The octave of a note following an octave check is determined with
respect to the note preceding it. In the next fragment, the last note
is a @code{a'}, above central C. Hence, the @code{\octave} check may
be deleted without changing the meaning of the piece.

@lilypond[verbatim,fragment] 
   \relative c' {
     e
     \octave b
     a        
   }
@end lilypond



@node Bar check
@subsection Bar check
@cindex Bar check

@cindex bar check
@cindex @code{barCheckSynchronize}
@cindex @code{|}

Bar checks help detect errors in the durations.  A bar check is
entered using the bar symbol, `@code{|}'.  Whenever it is encountered
during interpretation, it should fall on a measure boundary.  If it
does not, a warning is printed.  Depending on the value of
@code{barCheckSynchronize}, the beginning of the measure will be
relocated.

In the next example, the second bar check will signal an error:
@example
  \time 3/4 c2 e4 | g2 | 
@end example



@cindex skipTypesetting

Failed bar checks are caused by entering incorrect
durations. Incorrect durations often completely garble up the score,
especially if it is polyphonic, so you should start correcting the
score by scanning for failed bar checks and incorrect durations.  To
speed up this process, you can use @code{skipTypesetting}, described
in the next section.

@node Skipping corrected music
@subsection Skipping corrected music

The property @code{Score.skipTypesetting} can be used to switch on and
off typesetting completely during the interpretation phase. When
typesetting is switched off, the music is processed much more quickly.
This can be used to skip over the parts of a score that have already
been checked for errors:

@lilypond[fragment,singleline,verbatim]
\relative c'' { c8 d
\property Score.skipTypesetting = ##t
  e f g a g c, f e d
\property Score.skipTypesetting = ##f
c d b bes a g c2 } 
@end lilypond

@node Automatic note splitting 
@subsection Automatic note splitting

Long notes can be converted automatically to tied notes.  This is done
by replacing the @internalsref{Note_heads_engraver} by the
@internalsref{Completion_heads_engraver}:

@example
  \paper @{ \translator @{
      \ThreadContext
      \remove "Note_heads_engraver"
      \consists "Completion_heads_engraver"
  @} @}
@end example

which will make long notes tied in the following example:
@example
  \time 2/4
  c2. c8 d4 e f g a b c8 c2 b4 a g16 f4 e d c8. c2 
@end example

@lilypond[noindent]
\score{
  \notes\relative c'{
  \time 2/4
  c2. c8 d4 e f g a b c8 c2 b4 a g16 f4 e d c8. c2 
  }
  \paper { \translator {
      \ThreadContext
      \remove "Note_heads_engraver"
      \consists "Completion_heads_engraver"
  } }
  }
@end lilypond

This engraver splits all running notes at the bar line, and inserts
ties.  One of its uses is to debug complex scores: if the measures are
not entirely filled, then the ties exactly show how much each measure
is off.

@refbugs

Not all durations (especially those containing tuplets) can be
represented exactly; the engraver will not insert tuplets. 




@node Staff notation
@section Staff notation

This section describes music notation that occurs on staff level,
such as keys, clefs and time signatures.

@cindex Staff notation

@menu
* Staff symbol::                
* Key signature::               
* Clef::                        
* Ottava brackets::             
* Time signature::              
* Partial measures::            
* Unmetered music::             
* Bar lines::                   
@end menu

@node Staff symbol
@subsection Staff symbol

@cindex adjusting staff symbol
@cindex StaffSymbol, using \property
@cindex staff lines, setting number of

Notes, dynamic signs, etc. are grouped
with a set of horizontal lines, into a staff (plural `staves'). In our
system, these lines are drawn using a separate layout object called
staff symbol.  

This object is created whenever a @internalsref{Staff} context is
created.  The appearance of the staff symbol cannot be changed by
using @code{\override} or @code{\set}.  At the moment that
@code{\property Staff} is interpreted, a @internalsref{Staff} context
is made, and the @internalsref{StaffSymbol} is created before any
@code{\override} is effective. Properties can be changed in a
@code{\translator} definition, or by using @code{\outputproperty}.

@refbugs

If a staff is ended halfway a piece, the staff symbol may not end
exactly on the barline.


@node Key signature
@subsection Key signature
@cindex Key signature

@cindex @code{\key}

The key signature indicates the scale in which a piece is played. It
is denoted by a set of alterations (flats or sharps) at the start of
the staff.

@syntax

Setting or changing the key signature is done with the @code{\key}
command:
@example
  @code{\key} @var{pitch} @var{type}
@end example

@cindex @code{\minor}
@cindex @code{\major}
@cindex @code{\minor}
@cindex @code{\ionian}
@cindex @code{\locrian}
@cindex @code{\aeolian}
@cindex @code{\mixolydian}
@cindex @code{\lydian}
@cindex @code{\phrygian}
@cindex @code{\dorian}

Here, @var{type} should be @code{\major} or @code{\minor} to get
@var{pitch}-major or @var{pitch}-minor, respectively.
The standard mode names @code{\ionian},
@code{\locrian}, @code{\aeolian}, @code{\mixolydian}, @code{\lydian},
@code{\phrygian}, and @code{\dorian} are also defined.

This command sets the context property
@internalsref{Staff}.@code{keySignature}.  Non-standard key signatures
can be specified by setting this property directly.

@refbugs

The ordering of a key cancellation is wrong when it is combined with
repeat bar lines. The cancellation is also printed after a line break.

@seealso

@internalsref{KeyChangeEvent}, and @internalsref{KeySignature}.

@cindex @code{keySignature}


@node Clef
@subsection Clef
@cindex @code{\clef}

The clef indicates which lines of the staff correspond to which
pitches.

@syntax

The clef can be set or changed with the @code{\clef} command:
@lilypond[fragment,verbatim]
  \key f\major  c''2 \clef alto g'2
@end lilypond

Supported clef-names include:
@c Moved standard clefs to the top /MB
@table @code
@item treble, violin, G, G2
G clef on 2nd line
@item alto, C
 C clef on 3rd line
@item tenor
 C clef on 4th line
@item bass, F
 F clef on 4th line
@item french
 G clef on 1st line, so-called French violin clef
@item soprano
 C clef on 1st line
@item mezzosoprano
 C clef on 2nd line
@item baritone
 C clef on 5th line
@item varbaritone
 F clef on 3rd line
@item subbass
 F clef on 5th line
@item percussion
 percussion clef
@end table

By adding @code{_8} or @code{^8} to the clef name, the clef is
transposed one octave down or up, respectively. Argument @var{clefname} 
must be enclosed in quotes when it contains underscores or digits. For
example,
@example
        \clef "G_8"
@end example

This command is equivalent to setting @code{clefGlyph},
@code{clefPosition} (which controls the Y position of the clef),
@code{centralCPosition} and @code{clefOctavation}. A clef is printed
when any of these properties are changed.

@seealso

The object for this symbol is @internalsref{Clef}.



@node Ottava brackets
@subsection Ottava brackets

``Ottava'' brackets introduce an extra transposition of an octave for
the staff. They are created by invoking the function
@code{set-octavation}:

@cindex ottava
@cindex 15ma
@cindex octavation

@lilypond[verbatim,fragment]
\relative c''' {
  a2 b
  #(set-octavation 1)
  a b 
  #(set-octavation 0)
  a b }
@end lilypond

Internally the @code{set-octavation} function sets the properties
@code{ottavation} (eg. to @code{"8va"}) and @code{centralCPosition}.

@seealso

@internalsref{OttavaSpanner}.

@refbugs

@code{set-octavation} will get confused when clef changes happen
during an octavation bracket.

@node Time signature
@subsection Time signature
@cindex Time signature
@cindex meter
@cindex @code{\time}

Time signature indicates the metrum of a piece: a regular pattern of
strong and weak beats. It is denoted by a fraction at the start of the
staff.

@syntax

The time signature is set or changed by the @code{\time}
command:
@lilypond[fragment,verbatim]
 \time 2/4 c'2 \time 3/4 c'2. 
@end lilypond

The symbol that is printed can be customized with the @code{style}
property. Setting it to @code{#'()} uses fraction style for 4/4 and
2/2 time.  There are many more options for its layout.  See
@inputfileref{input/test,time.ly} for more examples.


This command sets the property @code{timeSignatureFraction},
@code{beatLength} and @code{measureLength} in the @code{Timing}
context, which is normally aliased to @internalsref{Score}.  The
property @code{measureLength} determines where bar lines should be
inserted, and how automatic beams should be generated.  Changing the
value of @code{timeSignatureFraction} also causes the symbol to be
printed.

More options are available through the Scheme function
@code{set-time-signature}. In combination with the
@internalsref{Measure_grouping_engraver}, it will create
@internalsref{MeasureGrouping} signs. Such signs ease reading
rhythmically complex modern music.  In the following example, the 9/8
measure is subdivided in 2, 2, 2 and 3. This is passed to
@code{set-time-signature} as the third argument @code{(2 2 2 3)}:

@lilypond[verbatim]
\score { \notes \relative c'' {
   #(set-time-signature 9 8 '(2 2 2 3))
   g8[ g] d[ d] g[ g] a8[( bes g]) | 
   #(set-time-signature 5 8 '(3 2))
   a4. g4
   }
   \paper {
       raggedright = ##t
       \translator { \StaffContext
         \consists "Measure_grouping_engraver"
   }}}
@end lilypond 

@seealso

@internalsref{TimeSignature}, and @internalsref{Timing_engraver}.


@refbugs

Automatic beaming does not use measure grouping specified with
@code{set-time-signature}.

@node Partial measures
@subsection Partial measures
@cindex Partial
@cindex anacrusis
@cindex partial measure
@cindex measure, partial
@cindex shorten measures
@cindex @code{\partial}

Partial measures, for example in upsteps, are entered using the
@code{\partial} command:
@lilypond[fragment,verbatim]
\partial 16*5  c'16 c4 |   a'2. ~ a'8. a'16 | g'1
@end lilypond

The syntax for this command is 
@example
  \partial @var{duration} 
@end example
This is  internally translated into
@example
  \property Timing.measurePosition = -@var{length of duration}
@end example
@cindex @code{|}
The property @code{measurePosition} contains a rational number
indicating how much of the measure has passed at this point.

@node Unmetered music
@subsection Unmetered music

Bar lines and bar numbers are calculated automatically. For unmetered
music (e.g. cadenzas), this is not desirable.  By setting
@code{Score.timing} to false, this automatic timing can be switched
off.


@refcommands

@cindex @code{\cadenzaOn}
@code{\cadenzaOn}, 
@cindex @code{\cadenzaOff}
@code{\cadenzaOff}.

@node Bar lines
@subsection Bar lines
@cindex Bar lines

@cindex @code{\bar}
@cindex measure lines
@cindex repeat bars


Bar lines delimit measures, but are also used to indicate repeats.
Normally, they are inserted automatically.  Line breaks may only
happen on barlines.

@syntax

 Special types
of barlines can be forced with the @code{\bar} command:
@lilypond[relative=1,fragment,verbatim]
   c4 \bar "|:" c4
@end lilypond

The following bar types are available:
@lilypond[fragment,  relative, singleline, verbatim]
c4
\bar "|" c
\bar "" c
\bar "|:" c
\bar "||" c
\bar ":|" c
\bar ".|" c
\bar ".|." c
\bar "|." 
@end lilypond

In scores with many staves, a @code{\bar} command in one staff is
automatically applied to all staves. The resulting bar lines are
connected between different staves of a @internalsref{StaffGroup}:
@c
@lilypond[fragment, verbatim]
< \context StaffGroup <
  \newcontext Staff { e'4 d'
     \bar "||"
     f' e' }
  \newcontext Staff { \clef bass c4 g e g } >
\newcontext Staff { \clef bass c2 c2 } >
@end lilypond


The command @code{\bar @var{bartype}} is a short cut for doing
@code{\property Score.whichBar = @var{bartype}} Whenever
@code{whichBar} is set to a string, a bar line of that type is
created.  At the start of a measure it is set to
@code{defaultBarType}. The contents of @code{repeatCommands} are used
to override default measure bars.

Property @code{whichBar} can also be set directly, using @code{\property} 
or @code{\bar}.  These settings take precedence over the automatic
@code{whichBar} settings. 

@cindex whichBar
@cindex repeatCommands
@cindex defaultBarType

You are encouraged to use @code{\repeat} for repetitions.  See
@ref{Repeats}.



@seealso

@ref{Repeats}.


The bar line objects that are created at @internalsref{Staff} level
are called @internalsref{BarLine}, the bar lines that span staves are
@internalsref{SpanBar}s.

@cindex bar lines at start of system
@cindex start of system

The barlines at the start of each system are
@internalsref{SystemStartBar}, @internalsref{SystemStartBrace}, and
@internalsref{SystemStartBracket}.  They are spanner objects and
typically must be tuned from a @code{\translator} block.


@node Polyphony
@section Polyphony
@cindex polyphony

The easiest way to enter fragments with more than one voice on a staff
is to split chords using the separator @code{\\}.  You can use it for
small, short-lived voices or for single chords:

@lilypond[verbatim,fragment]
\context Staff \relative c'' {
 c4 < { f d e  } \\ { b c2 } > c4 < g' \\ b, \\  f' \\ d >
}
@end lilypond

The separator causes @internalsref{Voice} contexts to be
instantiated. They 
bear the names @code{"1"}, @code{"2"}, etc. In each of these
contexts, vertical direction of slurs, stems, etc. is set
appropriately.

This can also be done by instantiating @internalsref{Voice} contexts
by hand, and using @code{\voiceOne}, up to @code{\voiceFour} to assign
a stem directions and horizontal shift for each part:
@c

@lilypond[singleline, verbatim]
\relative c''
\context Staff < \newcontext Voice { \voiceOne cis2 b  }
  \newcontext Voice { \voiceThree b4 ais ~ ais4 gis4 } 
  \newcontext Voice { \voiceTwo fis4~  fis4 f ~ f  } >
@end lilypond

Normally, note heads with a different number of dots are not merged, but
when  the object property @code{merge-differently-dotted} is set in
the @internalsref{NoteCollision} object, they are merged:
@lilypond[verbatim,fragment,singleline]
\relative c'' \context Voice < {
     g8 g8 
     \property Staff.NoteCollision \override
        #'merge-differently-dotted = ##t
     g8 g8
  } \\ { g8.[ f16] g8.[ f16] } 
  >
@end lilypond

Similarly, you can merge half note heads with eighth notes, by setting
@code{merge-differently-headed}:
@lilypond[fragment, relative=2,verbatim]
\context Voice < {
    c8 c4.
    \property Staff.NoteCollision
      \override #'merge-differently-headed = ##t
    c8 c4. } \\ { c2 c2 } >
@end lilypond

LilyPond also vertically shifts rests that are opposite of a stem:


@lilypond[singleline,fragment,verbatim]
\context Voice < c''4 \\  r4 >
@end lilypond


@refcommands



@cindex @code{\oneVoice}
@code{\oneVoice}, 
@cindex @code{\voiceOne}
@code{\voiceOne}, 
@cindex @code{\voiceTwo}
@code{\voiceTwo}, 
@cindex @code{\voiceThree}
@code{\voiceThree}, 
@cindex @code{\voiceFour}
@code{\voiceFour}.

The following commands specify in what chords of the current voice
should be shifted: the outer voice has @code{\shiftOff}, and the inner
voices have @code{\shiftOn}, @code{\shiftOnn}, etc.


@cindex @code{\shiftOn}
@code{\shiftOn}, 
@cindex @code{\shiftOnn}
@code{\shiftOnn}, 
@cindex @code{\shiftOnnn}
@code{\shiftOnnn}, 
@cindex @code{\shiftOff}
@code{\shiftOff}.



@seealso

The objects responsible for resolving collisions are
@internalsref{NoteCollision} and @internalsref{RestCollision}.  See
also example files @inputfileref{input/regression,collision-dots.ly},
@inputfileref{input/regression,collision-head-chords.ly},
@inputfileref{input/regression,collision-heads.ly},
@inputfileref{input/regression,collision-mesh.ly}, and
@inputfileref{input/regression,collisions.ly}.


@refbugs

Resolving collisions is a intricate subject, and only a few situations
are handled. When LilyPond cannot cope, the @code{force-hshift}
property of the @internalsref{NoteColumn} object and pitched rests can
be used to override typesetting decisions.

When using @code{merge-differently-headed} with an upstem 8th or a shorter
note, and a downstem half note, the 8th note gets the wrong offset.

@node Beaming
@section Beaming

Beams are used to group short notes into chunks that are aligned with
the metrum. They are inserted automatically in most cases:

@lilypond[fragment,verbatim, relative=2]
\time 2/4 c8 c c c \time 6/8 c c c c8. c16  c8
@end lilypond

When these automatic decisions are not good enough, beaming can be
entered explicitly. It is also possible to define  beaming patterns
that differ from the defaults.

@seealso

@internalsref{Beam}. 


@cindex Automatic beams
@subsection Manual beams
@cindex beams, manual
@cindex @code{]}
@cindex @code{[}

In some cases it may be necessary to override the automatic beaming
algorithm.  For example, the auto beamer will not put beams over rests
or bar lines. Such beams are specified by manually: the begin and end
point are marked with @code{[} and @code{]}:

@lilypond[fragment,relative,verbatim]
  \context Staff {
    r4 r8[ g' a r8] r8 g[ | a] r8
  }
@end lilypond

@cindex @code{stemLeftBeamCount}

Normally, beaming patterns within a beam are determined automatically.
When this mechanism fouls up, the properties
@code{Voice.stemLeftBeamCount} and @code{Voice.stemRightBeamCount} can
be used to control the beam subdivision on a stem.  If either property
is set, its value will be used only once, and then it is erased.

@lilypond[fragment,relative,verbatim]
  \context Staff {
    f8[ r16 f g a]
    f8[ r16 \property Voice.stemLeftBeamCount = #1 f g a]
  }
@end lilypond
@cindex @code{stemRightBeamCount}


The property @code{subdivideBeams} can be set in order to subdivide
all 16th or shorter beams at beat positions, as defined by the
@code{beatLength} property .  This accomplishes the same effect as
twiddling with @code{stemLeftBeamCount} and @code{stemRightBeamCount},
but it take less typing:


@lilypond[relative=1,verbatim,noindent]
        c16[ c c c c c c c]
        \property Voice.subdivideBeams = ##t
        c16[ c c c c c c c]
        \property Score.beatLength = #(ly:make-moment 1 8)
        c16[ c c c c c c c]
@end lilypond
@cindex subdivideBeams

Kneed beams are inserted automatically, when a large gap is detected
between the note heads.  This behavior can be tuned through the object
property @code{auto-knee-gap}.

Normally, line breaks are forbidden when beams cross bar lines.  This
behavior can be changed by setting @code{allowBeamBreak}.

@cindex @code{allowBeamBreak}
@cindex beams and line breaks

@cindex beams, kneed
@cindex kneed beams
@cindex auto-knee-gap



@refbugs

@cindex Frenched staves

Automatically kneed beams cannot be used together with hidden staves.



@menu
* Setting automatic beam behavior ::  
@end menu

@ignore
@no de Beam typography
@sub section Beam typography

One of the strong points of LilyPond is how beams are formatted. Beams
are quantized, meaning that the left and right endpoints beams start
exactly on staff lines. Without quantization, small wedges of white
space appear between the beam and staff line, and this looks untidy.

Beams are also slope-damped: melodies that go up or down should also
have beams that go up or down, but the slope of the beams should be
less than the slope of the notes themselves.

Some beams should be horizontal. These are so-called concave beams. 

[TODO: some pictures.]
@end ignore


@node Setting automatic beam behavior 
@subsection Setting automatic beam behavior 

@cindex @code{autoBeamSettings}
@cindex @code{(end * * * *)}
@cindex @code{(begin * * * *)}
@cindex automatic beams, tuning
@cindex tuning automatic beaming

@c [TODO: use \applycontext]

In normal time signatures, automatic beams can start on any note but can
only end in a few positions within the measure: beams can end on a beat,
or at durations specified by the properties in
@code{Voice.autoBeamSettings}. The defaults for @code{autoBeamSettings}
are defined in @file{scm/auto-beam.scm}.

The value of @code{autoBeamSettings} is changed using
@code{\override} and restored with @code{\revert}:
@example
\property Voice.autoBeamSettings \override #'(@var{BE} @var{P} @var{Q} @var{N} @var{M}) = @var{dur}
\property Voice.autoBeamSettings \revert #'(@var{BE} @var{P} @var{Q} @var{N} @var{M})
@end example
Here, @var{BE} is the symbol @code{begin} or @code{end}. It determines
whether the rule applies to begin or end-points.  The quantity
@var{P}/@var{Q} refers to the length of the beamed notes (and `@code{*
*}' designates notes of any length), @var{N}/@var{M} refers to a time
signature (wildcards, `@code{* *}' may be entered to designate all time
signatures).

For example, if automatic beams should end on every quarter note, use
the following:
@example
\property Voice.autoBeamSettings \override
    #'(end * * * *) = #(ly:make-moment 1 4)
@end example
Since the duration of a quarter note is 1/4 of a whole note, it is
entered as @code{(ly:make-moment 1 4)}.

The same syntax can be used to specify beam starting points. In this
example, automatic beams can only end on a dotted quarter note:
@example
\property Voice.autoBeamSettings \override
    #'(end * * * *) = #(ly:make-moment 3 8)
@end example
In 4/4 time signature, this means that automatic beams could end only on
3/8 and on the fourth beat of the measure (after 3/4, that is 2 times
3/8 has passed within the measure).

Rules can also be restricted to specific time signatures. A rule that
should only be applied in @var{N}/@var{M} time signature is formed by
replacing the second asterisks by @var{N} and @var{M}. For example, a
rule for 6/8 time exclusively looks like
@example
\property Voice.autoBeamSettings \override
    #'(begin * * 6 8) =  ... 
@end example

If a rule should be to applied only to certain types of beams, use the
first pair of asterisks. Beams are classified according to the
shortest note they contain. For a beam ending rule that only applies
to beams with 32nd notes (and no shorter notes), use @code{(end 1 32 *
*)}.

If a score ends while an automatic beam has not been ended and is still
accepting notes, this last beam will not be typeset at all.

@cindex automatic beam generation
@cindex autobeam
@cindex @code{Voice.autoBeaming}
@cindex lyrics

For melodies that have lyrics, you may want to switch off 
automatic beaming. This is done by setting @code{Voice.autoBeaming} to
@code{#f}. 

@refcommands

@cindex @code{\autoBeamOff}
@code{\autoBeamOff}, 
@cindex @code{\autoBeamOn}
@code{\autoBeamOn}.


@refbugs

The rules for ending a beam depend on the shortest note in a beam.
So, while it is possible to have different ending rules for eight
beams and sixteenth beams, a beam that contains both eight and
sixteenth notes will use the rules for the sixteenth beam.

In the example below, the autobeamer makes eight beams and sixteenth
end at 3 eights; the third beam can only be corrected by specifying
manual beaming.

@lilypond[singleline,fragment,relative,noverbatim,quote]
  \property Voice.autoBeamSettings
  \override #'(end * * * *) = #(ly:make-moment 3 8)
  % rather show case where it goes wrong
  %\time 12/8 c'8 c c c16 c c c c c c[ c c c] c8[ c] c4
  \time 12/8 c'8 c c c16 c c c c c c c c c c8 c c4
@end lilypond
It is not possible to specify beaming parameters that act differently in
different parts of a measure. This means that it is not possible to use
automatic beaming in irregular meters such as @code{5/8}.

@node Accidentals
@section Accidentals
@cindex Accidentals

This section describes how to change the way that accidentals are
inserted automatically before the running notes.


@menu
* Using the predefined accidental variables::  
* Customized accidental rules::  
@end menu

@node Using the predefined accidental variables
@subsection Using the predefined accidental variables

The constructs for describing the accidental typesetting rules are
quite hairy, so non-experts should stick to the variables
defined in @file{ly/property-init.ly}.
@cindex @file{property-init.ly}

The variables set properties in the ``@code{Current}'' context (see
@ref{Context properties}). This means that the variables should
normally be added right after the creation of the context in which the
accidental typesetting described by the variable is to take
effect. For example, if you want to use piano-accidentals in a piano
staff then issue @code{\pianoAccidentals} first thing after the
creation of the piano staff:
@example
\score @{
    \notes \relative c'' <
        \newcontext Staff @{ cis4 d e2 @}
        \context GrandStaff <
            \pianoAccidentals
            \newcontext Staff @{ cis4 d e2 @}
            \newcontext Staff @{ es2 c @}
        >
        \newcontext Staff @{ es2 c @}
    >
@}
@end example
@lilypond[singleline]
\score {
    \notes \relative c'' <
        \newcontext Staff { cis4 d e2 }
        \context GrandStaff <
            \pianoAccidentals
            \newcontext Staff { cis4 d e2 }
            \newcontext Staff { es2 c }
        >
        \newcontext Staff { es2 c }
    >
    \paper {
        \translator {
            \StaffContext
            minimumVerticalExtent = #'(-4.0 . 4.0)
        }
    }
}
@end lilypond

The variables are:
@table @code
@item \defaultAccidentals
      @cindex @code{\defaultAccidentals}
      This is the default typesetting behaviour. It should correspond
      to 18th century common practice: Accidentals are
      remembered to the end of the measure in which they occur and
      only on their own octave.

@item \voiceAccidentals
      @cindex @code{\voiceAccidentals}
@c
      The normal behaviour is to
remember the accidentals on Staff-level.  This variable, however,
typesets accidentals individually for each voice.  Apart from that the
rule is similar to @code{\defaultAccidentals}.

      This leads to some weird and often unwanted results
      because accidentals from one voice do not get cancelled in other
      voices:
@lilypond[singleline,relative,fragment,verbatim,quote]
    \context Staff <
        \voiceAccidentals
        <
         { es g } \\
         { c, e }
     > >
@end lilypond
      Hence you should only use @code{\voiceAccidentals} if the voices
are to be read solely by individual musicians. If the staff is to be
used by one musician (e.g. a conductor) then you use
@code{\modernVoiceAccidentals} or @code{\modernVoiceCautionaries}
instead.

@item \modernAccidentals
      @cindex @code{\modernAccidentals}
      This rule  corresponds to the common practice in the 20th
      century.
      The rule is  more complex than @code{\defaultAccidentals}.
      You get all the same accidentals, but temporary
      accidentals also get cancelled in other octaves. Furthermore,
      in the same octave, they also get cancelled in the following measure:
@lilypond[singleline,fragment,verbatim]
      \modernAccidentals
      cis' c'' cis'2 | c'' c'
@end lilypond

@item \modernCautionaries
      @cindex @code{\modernCautionaries}
     This rule is similar to @code{\modernAccidentals}, but the
     ``extra'' accidentals (the ones not typeset by
     @code{\defaultAccidentals}) are typeset as cautionary accidentals.
     They are printed in reduced size or with parentheses:
@lilypond[singleline,fragment,verbatim]
      \modernCautionaries
      cis' c'' cis'2 | c'' c'
@end lilypond

      @cindex @code{\modernVoiceAccidentals}
@item \modernVoiceAccidentals
is used for multivoice accidentals to be read both by musicians
playing one voice and musicians playing all voices.  Accidentals are
typeset for each voice, but they @emph{are} cancelled across voices in
the same @internalsref{Staff}.

      @cindex @code{\modernVoiceCautionaries}
@item \modernVoiceCautionaries
is the same as @code{\modernVoiceAccidentals}, but with the extra
accidentals (the ones not typeset by @code{\voiceAccidentals}) typeset
as cautionaries.  Even though all accidentals typeset by
@code{\defaultAccidentals} @emph{are} typeset by this variable then
some of them are typeset as cautionaries.

@item \pianoAccidentals
      @cindex @code{\pianoAccidentals}
      20th century practice for piano notation. Very similar to
      @code{\modernAccidentals} but accidentals also get cancelled
      across the staves in the same @internalsref{GrandStaff} or
      @internalsref{PianoStaff}.

@item \pianoCautionaries
      @cindex @code{\pianoCautionaries}
      As @code{\pianoAccidentals} but with the extra accidentals
      typeset as cautionaries.

@item \noResetKey
      @cindex @code{\noResetKey}
      Same as @code{\defaultAccidentals} but with accidentals lasting
      ``forever'' and not only until the next measure:
@lilypond[singleline,fragment,verbatim,relative]
      \noResetKey
      c1 cis cis c
@end lilypond

@item \forgetAccidentals
      @cindex @code{\forgetAccidentals}
      This is sort of the opposite of @code{\noResetKey}: Accidentals
      are not remembered at all---and hence all accidentals are
      typeset relative to the key signature, regardless of what was
      before in the music:
@lilypond[singleline,fragment,verbatim,relative]
      \forgetAccidentals
      \key d\major c4 c cis cis d d dis dis
@end lilypond
@end table

@node Customized accidental rules
@subsection  Customized accidental rules

This section must be considered gurus-only, and hence it must be
sufficient with a short description of the system and a reference to
the internal documentation.

The algorithm tries several different rules, and uses the rule
that gives the highest number of accidentals.  Each rule consists of
@table @var
@item context:
      In which context is the rule applied. For example, if
@var{context} is @internalsref{Score} then all staves share
accidentals, and if @var{context} is @internalsref{Staff} then all
voices in the same staff share accidentals, but staves do not.
@item octavation:
      Whether the accidental changes all octaves or only the current
      octave.
@item lazyness:
      Over how many barlines the accidental lasts.
      If @var{lazyness} is @code{-1} then the accidental is forget
      immediately, and if @var{lazyness} is @code{#t} then the accidental
      lasts forever.

@c [TODO: should use  +infinity for this case?]

@end table

@refcommands

@cindex @code{\defaultAccidentals}
@code{\defaultAccidentals}, 
@cindex @code{\voiceAccidentals}
@code{\voiceAccidentals}, 
@cindex @code{\modernAccidentals}
@code{\modernAccidentals}, 
@cindex @code{\modernCautionaries}
@code{\modernCautionaries}, 
@cindex @code{\modernVoiceAccidentals}
@code{\modernVoiceAccidentals}, 
@cindex @code{\modernVoiceCautionaries}
@code{\modernVoiceCautionaries}, 
@cindex @code{\pianoAccidentals}
@code{\pianoAccidentals}, 
@cindex @code{\pianoCautionaries}
@code{\pianoCautionaries}, 
@cindex @code{\noResetKey}
@code{\noResetKey}, 
@cindex @code{\forgetAccidentals}
@code{\forgetAccidentals}.

@seealso

@internalsref{Accidental_engraver}, @internalsref{Accidental}, and
@internalsref{AccidentalPlacement}.


@refbugs

Currently the simultaneous notes are considered to be entered in
sequential mode. This means that in a chord the accidentals are
typeset as if the notes in the chord happened once at a time - in the
order in which they appear in the input file.

This is only a problem when there are simultaneous notes whose
accidentals depend on each other.  The problem only occurs when using
non-default accidentals. In the default scheme, accidentals only
depend on other accidentals with the same pitch on the same staff, so
no conflicts possible.

This example shows two examples of the same music giving different
accidentals depending on the order in which the notes occur in the
input file:

@lilypond[singleline,fragment,verbatim]
\property Staff.autoAccidentals = #'( Staff (any-octave . 0) )
cis'4 <<c'' c'>> r2 | cis'4 <<c' c''>> r2
| <<cis' c''>> r | <<c'' cis'>> r | 
@end lilypond

This problem can be solved by manually inserting @code{!} and @code{?}
for the problematic notes.

@node Expressive marks
@section Expressive marks

@menu
* Slurs ::                      
* Phrasing slurs::              
* Breath marks::                
* Metronome marks::             
* Text spanners::               
* Analysis brackets::           
@end menu

@node Slurs 
@subsection Slurs
@cindex Slurs

A slur indicates that notes are to be played bound or @emph{legato}.

@syntax

They are entered using parentheses:
@lilypond[fragment,verbatim,center]
  f'( g')( a') a'8[ b'(] a'4 g'2 f'4)
  <<c' e'>>2( <<b d'>>2)
@end lilypond


@c TODO: should explain that ^( and _( set directions
@c should set attachments with ^ and _ ?  

Slurs avoid crossing stems, and are generally attached to note heads.
However, in some situations with beams, slurs may be attached to stem
ends.  If you want to override this layout you can do this through the
object property @code{attachment} of @internalsref{Slur} in
@internalsref{Voice} context.  Its value is a pair of symbols, specifying
the attachment type of the left and right end points:

@lilypond[fragment,relative,verbatim]
  \slurUp
  \property Voice.Stem \set #'length = #5.5
  g'8(g g4)
  \property Voice.Slur \set #'attachment = #'(stem . stem)
  g8( g g4)
@end lilypond

If a slur would strike through a stem or beam, the slur will be moved
away upward or downward. If this happens, attaching the slur to the
stems might look better:

@lilypond[fragment,relative,verbatim]
  \stemUp \slurUp
  d32( d'4 d8..)
  \property Voice.Slur \set #'attachment = #'(stem . stem)
  d,32( d'4 d8..)
@end lilypond

@refcommands


@cindex @code{\slurUp}
@code{\slurUp}, 
@cindex @code{\slurDown}
@code{\slurDown}, 
@cindex @code{\slurBoth}
@code{\slurBoth}, 
@cindex @code{\slurDotted}
@code{\slurDotted}, 
@cindex @code{\slurSolid}
@code{\slurSolid}.

@seealso

@seeinternals{Slur}, and @internalsref{SlurEvent}.


@refbugs

Producing nice slurs is a difficult problem, and LilyPond currently
uses a simple, empiric method to produce slurs. In some cases, its
results are ugly.


@cindex Adjusting slurs

@node Phrasing slurs
@subsection Phrasing slurs

@cindex phrasing slurs
@cindex phrasing marks

A phrasing slur (or phrasing mark) connects chords and is used to
indicate a musical sentence. It is started using @code{\(} and @code{\)}
respectively:

@lilypond[fragment,verbatim,center,relative]
  \time 6/4 c'\(  d( e) f( e)  d\) 
@end lilypond

Typographically, the phrasing slur behaves almost exactly like a
normal slur.  However, they are treated as different objects.  A
@code{\slurUp} will have no effect on a phrasing slur; instead, you
should use @code{\phrasingSlurUp}, @code{\phrasingSlurDown}, and
@code{\phrasingSlurBoth}.

The commands @code{\slurUp}, @code{\slurDown}, and @code{\slurBoth}
will only affect normal slurs and not phrasing slurs.

@refcommands

@cindex @code{\phrasingSlurUp}
@code{\phrasingSlurUp}, 
@cindex @code{\phrasingSlurDown}
@code{\phrasingSlurDown}, 
@cindex @code{\phrasingSlurBoth}
@code{\phrasingSlurBoth}, 

@seealso

See also @internalsref{PhrasingSlur}, and
@internalsref{PhrasingSlurEvent}.

@refbugs

Phrasing slurs have the same limitations in their formatting as normal
slurs. Putting phrasing slurs over rests leads to spurious warnings.

@node Breath marks
@subsection Breath marks

Breath marks are entered using @code{\breathe}:


@lilypond[fragment,relative,verbatim]
c'4 \breathe d4
@end lilypond

The glyph of the breath mark can be tweaked by overriding the
@code{text} property of the @code{BreathingSign} layout object with the name of
any glyph of @ref{The Feta font}.  For example,
@lilypond[fragment,verbatim,relative]
c'4
\property Voice.BreathingSign \override #'text = #"scripts-rvarcomma"
\breathe
d4
@end lilypond

@seealso 

@internalsref{BreathingSign}, @internalsref{BreathingSignEvent}, and
@inputfileref{input/regression,breathing-sign.ly}.


@node Metronome marks
@subsection Metronome marks

@cindex Tempo
@cindex beats per minute
@cindex metronome marking

Metronome settings can be entered as follows:
@example 
  \tempo @var{duration} = @var{perminute} 
@end example

In the MIDI output, they are interpreted as a tempo change, and in the
paper output, a metronome marking is printed:
@cindex @code{\tempo}
@lilypond[fragment,verbatim]
  \tempo 8.=120 c''1
@end lilypond

@seealso

@internalsref{MetronomeChangeEvent}.
  


@node Text spanners
@subsection Text spanners
@cindex Text spanners

Some performance indications, e.g. @i{rallentando} or @i{accelerando},
are written as texts, and extended over many measures with dotted
lines.  You can create such texts using text spanners: attach
@code{\startTextSpan} and @code{\stopTextSpan} to the
start and ending note of the spanner. 

The string to be printed, as well as the style, is set through object
properties:

@lilypond[fragment,relative,verbatim]
 \relative c' {  c1 
  \property Voice.TextSpanner \set #'direction = #-1
  \property Voice.TextSpanner \set #'edge-text = #'("rall " . "")
  c2\startTextSpan b c\stopTextSpan a }
@end lilypond


@seealso

@internalsref{TextSpanEvent},
@internalsref{TextSpanner}, and
@inputfileref{input/regression,text-spanner.ly}.


@node Analysis brackets
@subsection Analysis brackets
@cindex brackets
@cindex phrasing brackets
@cindex musicological analysis
@cindex note grouping bracket

Brackets are used in musical analysis to indicate structure in musical
pieces. LilyPond supports a simple form of nested horizontal brackets.
To use this, add the @internalsref{Horizontal_bracket_engraver} to
@internalsref{Staff} context.  A bracket is started with
@code{\startGroup} and closed with @code{\stopGroup}:

@lilypond[singleline,verbatim]
\score { \notes \relative c'' {  
        c4\startGroup\startGroup
        c4\stopGroup
        c4\startGroup
        c4\stopGroup\stopGroup
  }
  \paper { \translator {
            \StaffContext \consists "Horizontal_bracket_engraver"
        }}}
@end lilypond

@seealso

@internalsref{HorizontalBracket}, @internalsref{NoteGroupingEvent}, and
@inputfileref{input/regression,note-group-bracket.ly}. 


@node Articulations
@section Articulations
@cindex Articulations

@cindex articulations
@cindex scripts
@cindex ornaments

A variety of symbols can appear above and below notes to indicate
different characteristics of the performance. They are added to a note
by adding a dash and  the character signifying the
articulation. They are demonstrated here:

@lilypondfile[notexidoc]{script-abbreviations.ly}

The meanings of these shorthands can be changed: see
@file{ly/script-init.ly} for examples.


The script is automatically placed, but if you need to force
directions, you can use @code{_} to force them down, or @code{^} to
put them up:
@lilypond[fragment, verbatim]
  c''4^^ c''4_^
@end lilypond

Other symbols can be added using the syntax
@var{note}@code{\}@var{name}, e.g. @code{c4\fermata}. Again, they
can be forced up or down using @code{^} and @code{_},
eg.

@lilypond[verbatim,fragment,relative 2]
  c\fermata c^\fermata c_\fermata
@end lilypond



@cindex accent
@cindex marcato
@cindex staccatissimo
@cindex fermata
@cindex stopped
@cindex staccato
@cindex portato
@cindex tenuto
@cindex upbow
@cindex downbow
@cindex foot marks
@cindex organ pedal marks
@cindex turn
@cindex open
@cindex flageolet
@cindex reverseturn
@cindex trill
@cindex prall
@cindex mordent
@cindex prallprall
@cindex prallmordent
@cindex prall, up
@cindex prall, down
@cindex mordent
@cindex thumb marking
@cindex segno
@cindex coda
@cindex varcoda

@lilypondfile[notexidoc]{script-chart.ly}


@refcommands

@cindex @code{\scriptUp}
@code{\scriptUp}, 
@cindex @code{\scriptDown}
@code{\scriptDown}, 
@cindex @code{\scriptBoth}
@code{\scriptBoth}.

@seealso

@internalsref{ScriptEvent}, and @internalsref{Script}.

@refbugs

All of these note ornaments appear in the printed output but have no
effect on the MIDI rendering of the music.


@node Fingering instructions
@section Fingering instructions

@cindex fingering

Fingering instructions can be entered using
@example
  @var{note}-@var{digit}
@end example
For finger changes, use markup texts:
@c
@lilypond[verbatim, singleline, fragment]
      c'4-1 c'4-2 c'4-3 c'4-4
      c'^\markup { \fontsize #-3 \number "2-3" }
@end lilypond

@cindex finger change
@cindex scripts
@cindex superscript
@cindex subscript

You can use the thumb-script to indicate that a note should be
played with your thumb (used in cello music):

@lilypond[verbatim, singleline, fragment]
      <<a' a''-3>>8(_\thumb[ <<b' b''-3>>)_\thumb
      <<c'' c'''-3>>(_\thumb <<d'' d'''-3>>)_\thumb]
@end lilypond

Fingerings for chords can also be added to individual notes
of the chord by adding them after the pitches:
@lilypond[verbatim,singleline,fragment,relative=1]
        << c-1  e-2 g-3 b-5 >> 4
@end lilypond

Setting @code{fingerHorizontalDirection} will put the fingerings next
to the note head:

@lilypond[verbatim,singleline,fragment,relative=1]
        \property Voice.fingerHorizontalDirection = #LEFT
        << c-1  es-2 g-4 bes-5 >> 4
        \property Voice.fingerHorizontalDirection = #RIGHT
        << c-1  es-2 g-4 bes-5 >> 4
@end lilypond
        
@seealso

@internalsref{FingerEvent}, and @internalsref{Fingering}.


@menu
* Text scripts::                
* Grace notes::                 
* Glissando ::                  
* Dynamics::                    
@end menu

@node Text scripts
@subsection Text scripts
@cindex Text scripts

It is possible to place arbitrary strings of text or markup text (see
@ref{Text markup}) above or below notes by using a string:
@code{c^"text"}.  By default, these indications do not influence the
note spacing, but by using the command @code{\fatText}, the widths
will be taken into account:
@c
@lilypond[fragment,singleline,verbatim] \relative c' {
c4^"longtext" \fatText c4_"longlongtext" c4 }
@end lilypond

It is possible to use @TeX{} commands in the strings, but this should
be avoided because the exact dimensions of the string can then no
longer be computed.


@seealso

@internalsref{TextScriptEvent}, @internalsref{TextScript}, and
@ref{Text markup}.



@node Grace notes
@subsection Grace notes


@c should have blurb about accaciatura / appogiatura

@cindex @code{\grace}
@cindex ornaments
@cindex grace notes

Grace notes are ornaments that are written out, like accaciatura and
appogiatura notes.
@lilypond[relative=2,verbatim,fragment]
c4 \grace c16 c4 \grace {
c16[ d16] } c4
@end lilypond

From the point of view of typesetting, their characteristic is that
grace notes take up take up no logical time in a measure.  Internally,
timing for grace notes is done using a second time. Every point in
musical time consists of two rational numbers: one denotes the logical
time, one denotes the grace timing. The above example is shown here
with timing tuples:

@lilypond[]
\score { \notes \relative c''{ 
  c4^"(0,0)"  \grace c16_" "_"(1/4,-1/16)"  c4^"(1/4,0)"  \grace {
  c16_"(2/4,-1/8)"[  d16^"(2/4,-1/16)" ] } c4_" "_"(2/4,0)"
  }
\paper {  linewidth = 12.\cm }
}
@end lilypond


The placement of grace notes is synchronized between different staves.
In the following example, there are two sixteenth graces notes for
every eighth grace note:

@lilypond[relative=2,verbatim,fragment] 
< \newcontext Staff { e4 \grace { c16[ d e f] } e4 }
  \newcontext Staff { c'4 \grace { g8[ b] } c4 } >
@end lilypond


Unbeamed eighth notes and shorter by default have a slash through the
stem. These notes are called accaciaturas, and should generally be
played as short as possible. An appogiatura takes a fixed fraction of
the main note, is and denoted without a slash. 

Such slashless notes are obtained by setting the object property
@code{stroke-style} of the @internalsref{Stem} object. For proper
matching of override and reverts of such properties, it is necessary
to use a Scheme function.

The following fragment overrides the default formatting Grace style stems:
@example
  #(add-to-grace-init "Voice" 'Stem  'stroke-style '())
@end example

The @code{\override} is carefully matched with a @code{\revert}:

@cindex slash
@cindex grace slash

@lilypond[fragment,verbatim]
\relative c'' \context Voice {
  \grace c8 c4 \grace { c16[ c16] } c4
  \grace { 
    \property Voice.Stem \override #'stroke-style = #'() 
    c16 
    \property Voice.Stem \revert #'stroke-style
  } c4
}
@end lilypond

If you want to end a note with a grace note, then the standard trick
is to put the grace notes before a phantom ``space note'', e.g.
@lilypond[fragment,verbatim, relative=2]
\context Voice {
    < { d1^\trill ( }
     { s2 \grace { c16[ d] } } >
   c4)
}
@end lilypond

@noindent
By adjusting the duration of the skip note (here it is a half-note),
the space between the main-note and the grace is adjusted.

A @code{\grace} section has some default values, and LilyPond will
use those default values unless you specify otherwise inside the
@code{\grace} section.  For example, if you specify \slurUp
@emph{before} your @code{\grace} section, a slur which starts inside
the @code{\grace} will not be forced up, even if the slur ends outside
of the @code{\grace}.  Note the difference between the first and
second bars in this example:

@lilypond[fragment,verbatim]
\relative c'' \context Voice {
    \slurUp
    \grace {
        a4( }
    a4) a4( a2)
    \slurBoth

    \grace {
        \slurUp
        a4( }
    a4) a4( a2)
    \slurBoth
}
@end lilypond


@seealso

@internalsref{GraceMusic}.

@refbugs

Grace notes cannot be used in the smallest size (@file{paper11.ly}).

A score that starts with an @code{\grace} section needs an explicit
@code{\context Voice} declaration, otherwise the main note and grace
note end up on different staves.

Grace note synchronization can also lead to surprises. Staff notation,
such as key signatures, barlines, etc. are also synchronized. Take
care when you mix staves with grace notes and staves without, for example,

@lilypond[relative=2,verbatim,fragment]
< \newcontext Staff { e4 \bar "|:" \grace c16 d4 }
  \newcontext Staff { c4 \bar "|:"  d4 } >
@end lilypond

Grace sections should only be used within sequential music
expressions.  Nesting or juxtaposing grace sections is not supported,
and might produce crashes or other errors.

Overriding settings for grace music globally cannot be done in a
modular way. A kludge (@code{add-to-grace-init}) is defined in
@file{ly/grace-init.ly}.


@node Glissando 
@subsection Glissando
@cindex Glissando 

@cindex @code{\glissando}

A glissando is a smooth change in pitch. It is denoted by a line or a
wavy line between two notes.

@syntax

A glissando line can be requested by attaching a @code{\glissando} to
a note:

@lilypond[fragment,relative,verbatim]
  c'-\glissando c'
@end lilypond

@seealso

@internalsref{Glissando}, and @internalsref{GlissandoEvent}.


@refbugs

Additional texts (such as @emph{gliss.}) is not supported.


@node Dynamics
@subsection Dynamics
@cindex Dynamics



@cindex @code{\ppp}
@cindex @code{\pp}
@cindex @code{\p}
@cindex @code{\mp}
@cindex @code{\mf}
@cindex @code{\f}
@cindex @code{\ff}
@cindex @code{\fff}
@cindex @code{\ffff}
@cindex @code{\fp}
@cindex @code{\sf}
@cindex @code{\sff}
@cindex @code{\sp}
@cindex @code{\spp}
@cindex @code{\sfz}
@cindex @code{\rfz}


Absolute dynamic marks are specified using an variable after a
note: @code{c4-\ff}.  The available dynamic marks are @code{\ppp},
@code{\pp}, @code{\p}, @code{\mp}, @code{\mf}, @code{\f}, @code{\ff},
@code{\fff}, @code{\fff}, @code{\fp}, @code{\sf}, @code{\sff},
@code{\sp}, @code{\spp}, @code{\sfz}, and @code{\rfz}:

@lilypond[verbatim,singleline,fragment,relative]
  c'-\ppp c-\pp c -\p c-\mp c-\mf c-\f c-\ff c-\fff
  c2-\sf c-\rfz
@end lilypond

@cindex @code{\cr}
@cindex @code{\rc}
@cindex @code{\decr}
@cindex @code{\rced}
@cindex @code{\<}
@cindex @code{\>}
@cindex @code{\"!}



A crescendo mark is started with @code{\<} and terminated with
@code{\!}. A decrescendo is started with @code{\>} and also terminated
with @code{\!}.  Because these marks are bound to notes, if you must
use spacer notes if multiple marks during one note are needed:

@lilypond[fragment,verbatim,center,quote]
  c''-\< c''-\!   d''-\decr e''-\rced 
  < f''1 { s4 s4-\< s4-\! \>  s4-\! } >
@end lilypond
This may give rise to very short hairpins. Use @code{minimum-length}
in @internalsref{Voice}.@internalsref{Hairpin} to lengthen them, for
example:

@example
 \property Staff.Hairpin \override #'minimum-length = #5
@end example

You can also use a text saying @emph{cresc.} instead of hairpins. Here
is an example how to do it:

@lilypond[fragment,relative=2,verbatim]
  c4 \cresc c4 c c c \endcresc c4
@end lilypond

@cindex crescendo
@cindex decrescendo

You can also supply your own texts:
@lilypond[fragment,relative,verbatim]
  \context Voice {
    \property Voice.crescendoText = \markup { \italic "cresc. poco" }
    \property Voice.crescendoSpanner = #'dashed-line
    a'2-\mf-\< a a a-\!
  }
@end lilypond

@cindex diminuendo


@refcommands

@cindex @code{\dynamicUp}
@code{\dynamicUp}, 
@cindex @code{\dynamicDown}
@code{\dynamicDown}, 
@cindex @code{\dynamicBoth}
@code{\dynamicBoth}.

@cindex direction, of dynamics

@seealso

@internalsref{CrescendoEvent}, @internalsref{DecrescendoEvent}, and
@internalsref{AbsoluteDynamicEvent}.

Dynamics are objects of @internalsref{DynamicText} and
@internalsref{Hairpin}. Vertical positioning of these symbols is
handled by the @internalsref{DynamicLineSpanner} object.

If you want to adjust padding or vertical direction of the dynamics, you 
must set properties for the @internalsref{DynamicLineSpanner} object.


@node Repeats
@section Repeats


@cindex repeats
@cindex @code{\repeat}


Repetition is a central concept in music, and multiple notations exist
for repetitions. In LilyPond, most of these notations can be captured
in a uniform syntax. One of the advantages is, all these repetitions
can be rendered in MIDI accurately.

The following types of repetition are supported:

@table @code
@item unfold
Repeated music is fully written (played) out.  Useful for MIDI
output, and entering repetitive music.

@item volta
This is the normal notation: Repeats are not written out, but
alternative endings (voltas) are printed, left to right.

@ignore
@item fold
Alternative endings are written stacked. This has limited use but may be
used to typeset two lines of lyrics in songs with repeats, see
@inputfileref{input,star-spangled-banner.ly}.
@end ignore

@item tremolo
Make tremolo beams.

@item percent
Make beat or measure repeats. These look like percent signs.

@end table  

@menu
* Repeat syntax::               
* Repeats and MIDI::            
* Manual repeat commands::      
* Tremolo repeats::             
* Tremolo subdivisions::        
* Measure repeats::             
@end menu

@node Repeat syntax
@subsection Repeat syntax

@syntax

LilyPond has one syntactic construct for specifying different types of
repeats.  The syntax is

@example
  \repeat @var{variant} @var{repeatcount} @var{repeatbody}
@end example

If you have alternative endings, you may add
@cindex @code{\alternative}
@example
 \alternative @code{@{} @var{alternative1}
            @var{alternative2}
            @var{alternative3} @dots{} @code{@}}
@end example
where each @var{alternative} is a music expression.  If you do not
give enough alternatives for all of the repeats, then the first
alternative is assumed to be played more than once.

Normal notation repeats are used like this:
@lilypond[fragment,verbatim]
  c'1
  \repeat volta 2 { c'4 d' e' f' }
  \repeat volta 2 { f' e' d' c' }
@end lilypond

With alternative endings:
@lilypond[fragment,verbatim]
  c'1
  \repeat volta 2 {c'4 d' e' f'} 
  \alternative { {d'2 d'} {f' f} }
@end lilypond


@lilypond[fragment,verbatim]
\context Staff {
  \relative c' {
    \partial 4
    \repeat volta 4 { e | c2 d2 | e2 f2 | }
    \alternative { { g4 g g } { a | a a a a | b2. } }
  }
}
@end lilypond

@refbugs

If you do a nested repeat like

@example 
\repeat @dots{}
\repeat @dots{}
\alternative 
@end example 

@noindent
then it is ambiguous to which @code{\repeat} the @code{\alternative}
belongs. This ambiguity is resolved by always having the
@code{\alternative} belong to the inner @code{\repeat}.  For clarity,
it is advisable to use braces in such situations.
@cindex ambiguity

@node Repeats and MIDI
@subsection Repeats and MIDI

@cindex expanding repeats

For instructions on how to unfold repeats for MIDI output, see the
example file @inputfileref{input/test,unfold-all-repeats.ly}.


@refbugs

Timing information is not remembered at the start of an alternative,
so after a repeat timing information must be reset by hand, for
example by setting @code{Score.measurePosition} or entering
@code{\partial}.  Similarly, slurs or ties are also not repeated.


@node Manual repeat commands
@subsection Manual repeat commands

@cindex @code{repeatCommands}

The property @code{repeatCommands} can be used to control the layout of
repeats. Its value is a Scheme list of repeat commands, where each repeat
command can be

@table @asis
@item the symbol @code{start-repeat},
  which prints a @code{|:} bar line,
@item the symbol @code{end-repeat},
  which prints a @code{:|} bar line,
@item the list @code{(volta @var{text})},
  which prints a volta bracket saying @var{text}: The text can be specified as
a text string or as a markup text, see @ref{Text markup}. Do not
forget to change the font, as the default number font does not contain
alphabetic characters. Or,
@item the list @code{(volta #f)}, which 
  stops a running volta bracket:
@end table

@lilypond[verbatim, fragment]
 c''4
    \property Score.repeatCommands = #'((volta "93") end-repeat)
 c''4 c''4
    \property Score.repeatCommands = #'((volta #f))
 c''4 c''4
@end lilypond


@seealso

@internalsref{VoltaBracket}, @internalsref{RepeatedMusic},
@internalsref{VoltaRepeatedMusic},
@internalsref{UnfoldedRepeatedMusic}, and
@internalsref{FoldedRepeatedMusic}.

@node Tremolo repeats
@subsection Tremolo repeats
@cindex tremolo beams

To place tremolo marks between notes, use @code{\repeat} with tremolo
style:
@lilypond[verbatim,center,singleline]
\score { 
  \context Voice \notes\relative c' {
    \repeat "tremolo" 8 { c16 d16 }
    \repeat "tremolo" 4 { c16 d16 }    
    \repeat "tremolo" 2 { c16 d16 }
    \repeat "tremolo" 4 c16
  }
}
@end lilypond

@seealso

Tremolo beams are @internalsref{Beam} objects. Single stem tremolos
are @internalsref{StemTremolo}s.  The music expression is
@internalsref{TremoloEvent}.


@refbugs

The single stem tremolo must be entered without @code{@{} and
@code{@}}.

@node Tremolo subdivisions
@subsection Tremolo subdivisions
@cindex tremolo marks
@cindex @code{tremoloFlags}

Tremolo marks can be printed on a single note by adding
`@code{:}[@var{length}]' after the note.  The length must be at least 8.
A @var{length} value of 8 gives one line across the note stem.  If the
length is omitted, then then the last value (stored in
@code{Voice.tremoloFlags}) is used:

@lilypond[verbatim,fragment,center]
  c'2:8 c':32 | c': c': |
@end lilypond

@c [TODO : stok is te kort bij 32en]

@refbugs

Tremolos in this style do not carry over into the MIDI output.


@node Measure repeats
@subsection Measure repeats

@cindex percent repeats
@cindex measure repeats

In the @code{percent} style, a note pattern can be repeated. It is
printed once, and then the pattern is replaced with a special sign.
Patterns of a one and two measures are replaced by percent-like signs,
patterns that divide the measure length are replaced by slashes:

@lilypond[verbatim,singleline]
 \context Voice { \repeat  "percent" 4  { c'4 }
    \repeat "percent" 2 { c'2 es'2 f'4 fis'4 g'4 c''4 }
}
@end lilypond   

@seealso

@internalsref{RepeatSlash}, @internalsref{PercentRepeat},
@internalsref{PercentRepeatedMusic}, and
@internalsref{DoublePercentRepeat}.



@node Rhythmic music
@section Rhythmic music

Sometimes you might want to show only the rhythm of a melody.  This
can be done with the rhythmic staff. All pitches of notes on such a
staff are squashed, and the staff itself has a single line:

@lilypond[fragment,relative,verbatim]
  \context RhythmicStaff {
      \time 4/4
      c4 e8 f  g2 | r4 g r2 | g1:32 | r1 |
  }
@end lilypond

@menu
* Percussion staves::           
* Percussion MIDI output::      
@end menu

@node Percussion staves
@subsection Percussion staves
@cindex percussion
@cindex drums

A percussion part for more than one instrument typically uses a
multiline staff where each position in the staff refers to one piece
of percussion.

@syntax

Percussion staves are typeset with help of a set of Scheme
functions. The system is based on the general MIDI drum-pitches.
Include @file{drumpitch-init.ly} to use drum pitches. This file
defines the pitches from the Scheme variable @code{drum-pitch-names},
the definition of which can be read in @file{scm/drums.scm}.  Each
piece of percussion has a full name and an abbreviated name, and either
the full name or the abbreviation may be used in input files.

To typeset the music on a staff apply the function @code{drums->paper}
to the percussion music. This function takes a list of percussion
instrument names, notehead scripts and staff positions (that is:
pitches relative to the C-clef) and transforms the input
music by moving the pitch, changing the notehead and (optionally)
adding a script:
@c
@lilypond[singleline,verbatim,quote]
\include "drumpitch-init.ly"
up = \notes { crashcymbal4 hihat8 halfopenhihat hh hh hh openhihat }
down = \notes { bassdrum4 snare8 bd r bd sn4 }
\score {
    \apply #(drums->paper 'drums) \context Staff <
        \clef percussion
        \newcontext Voice { \voiceOne \up }
        \newcontext Voice { \voiceTwo \down }
    >
}

@end lilypond
In the above example the music was transformed using the list @code{'drums}.
Currently the following lists are defined in @file{scm/drums.scm}:
@table @code
@item 'drums
to typeset a typical drum kit on a five-line staff:

@lilypond[noindent]
\include "drumpitch-init.ly"
nam = \lyrics { cymc cyms cymr hh hhc hho hhho hhp cb hc
    bd sn ss tomh tommh tomml toml tomfh tomfl }
mus = \notes  { cymc cyms cymr hh hhc hho hhho hhp cb hc
    bd sn ss tomh tommh tomml toml tomfh tomfl s16 }
\score {
    <
        \apply #(drums->paper 'drums) \context Staff <
            \clef percussion
            \mus
        >
        \context Lyrics \nam 
    >
    \paper {
        linewidth = 100.0\mm
        \translator {
            \StaffContext
            \remove Bar_engraver
            \remove Time_signature_engraver
            minimumVerticalExtent = #'(-4.0 . 5.0)
        }
        \translator {
            \VoiceContext
            \remove Stem_engraver
        }
   }   
}
@end lilypond

The drum scheme supports six different toms.  When there fewer toms, simply
select the toms that produce the desired result, i.e. to get toms on
the three middle lines you use @code{tommh}, @code{tomml} and
@code{tomfh}.

Because general MIDI does not contain rimshots the sidestick is used
for this purpose instead.
@item 'timbales
to typeset timbales on a two line staff:

@lilypond[singleline]
\include "drumpitch-init.ly"
nam = \lyrics { timh ssh timl ssl cb }
mus = \notes  { timh ssh timl ssl cb s16 }
\score {
    <
        \apply #(drums->paper 'timbales) \context Staff <
            \clef percussion
            \mus
        >
        \context Lyrics \nam 
    >
    \paper {
        \translator {
            \StaffContext
            \remove Bar_engraver
            \remove Time_signature_engraver
            StaffSymbol \override #'line-count = #2
            StaffSymbol \override #'staff-space = #2
            minimumVerticalExtent = #'(-3.0 . 4.0)
        }
        \translator {
            \VoiceContext
            \remove Stem_engraver
        }

    }   
}
@end lilypond
@item 'congas
to typeset congas on a two line staff:

@lilypond[singleline]
\include "drumpitch-init.ly"
nam = \lyrics { cgh cgho cghm ssh cgl cglo cglm ssl }
mus = \notes  { cgh cgho cghm ssh cgl cglo cglm ssl s16 }
\score {
    <
        \apply #(drums->paper 'congas) \context Staff <
            \clef percussion
            \mus
        >
        \context Lyrics \nam 
    >
    \paper {
        \translator {
            \StaffContext
            \remove Bar_engraver
            \remove Time_signature_engraver
            StaffSymbol \override #'line-count = #2
            StaffSymbol \override #'staff-space = #2
            minimumVerticalExtent = #'(-3.0 . 4.0)
        }
        \translator {
            \VoiceContext
            \remove Stem_engraver
        }
    }   
}
@end lilypond
@item 'bongos
to typeset bongos on a two line staff:

@lilypond[singleline]
\include "drumpitch-init.ly"
nam = \lyrics { boh boho bohm ssh bol bolo bolm ssl }
mus = \notes  { boh boho bohm ssh bol bolo bolm ssl s16 }
\score {
    <
        \apply #(drums->paper 'bongos) \context Staff <
            \clef percussion
            \mus
        >
        \context Lyrics \nam 
    >
    \paper {
        \translator {
            \StaffContext
            \remove Bar_engraver
            \remove Time_signature_engraver
            StaffSymbol \override #'line-count = #2
            StaffSymbol \override #'staff-space = #2
            minimumVerticalExtent = #'(-3.0 . 4.0)
        }
        \translator {
            \VoiceContext
            \remove Stem_engraver
        }
    }   
}
@end lilypond
@item 'percussion
to typeset all kinds of simple percussion on one line staves:
@lilypond[singleline]
\include "drumpitch-init.ly"
nam = \lyrics { tri trio trim gui guis guil cb cl tamb cab mar hc }
mus = \notes  { tri trio trim gui guis guil cb cl tamb cab mar hc s16 }
\score {
    <
        \apply #(drums->paper 'percussion) \context Staff <
            \clef percussion
            \mus
        >
        \context Lyrics \nam 
    >
    \paper {
        \translator {
            \StaffContext
            \remove Bar_engraver
            \remove Time_signature_engraver
            StaffSymbol \override #'line-count = #1
            minimumVerticalExtent = #'(-2.0 . 3.0)
        }
        \translator {
            \VoiceContext
            \remove Stem_engraver
        }
    }   
}
@end lilypond
@end table

If you do not like any of the predefined lists you can define your own
list at the top of your file:

@lilypond[singleline, verbatim]
#(set-drum-kit 'mydrums `(
        (bassdrum     default   #f        ,(ly:make-pitch -1 2 0))
        (snare        default   #f        ,(ly:make-pitch 0 1 0))
        (hihat        cross     #f        ,(ly:make-pitch 0 5 0))
        (pedalhihat   xcircle   "stopped" ,(ly:make-pitch 0 5 0))
        (lowtom       diamond   #f        ,(ly:make-pitch -1 6 0))
))
\include "drumpitch-init.ly"
up = \notes { hh8 hh hh hh hhp4 hhp }
down = \notes { bd4 sn bd toml8 toml }
\score {    
    \apply #(drums->paper 'mydrums) \context Staff <
        \clef percussion
        \newcontext Voice { \voiceOne \up }
        \newcontext Voice { \voiceTwo \down }
    >
}
@end lilypond

To use a modified existing list, one can prepend modifications to the
the existing list:

@example
#(set-drum-kit 'mydrums (append `(
   (bassdrum default #f ,(ly:make-pitch -1 2 0))
   (lowtom   diamond #f ,(ly:make-pitch -1 6 0))
) (get-drum-kit 'drums)))
@end example

You can easily combine percussion notation with pitched notation.
Indeed, the file @file{drumpitch-init.ly} replaces the normal pitch
names, so you will have to reinclude @file{nederlands.ly} after the
drum-pattern-definitions to enter normal notes:
@c
@lilypond[singleline,verbatim]
\include "drumpitch-init.ly"
up = \notes { crashcymbal4 hihat8 halfopenhihat hh hh hh openhihat }
down = \notes { bassdrum4 snare8 bd r bd sn4 }
\include "nederlands.ly"
bass = \notes \transpose c c,, { a4. e8 r e g e }
\score {
    <
        \apply #(drums->paper 'drums) \newcontext Staff <
            \clef percussion
            \newcontext Voice { \voiceOne \up }
            \newcontext Voice { \voiceTwo \down }
        >
        \newcontext Staff { \clef "F_8" \bass }
    >
}
@end lilypond

@node Percussion MIDI output
@subsection Percussion MIDI output

In order to produce correct MIDI output you need to produce two score
blocks---one for the paper and one for the MIDI output.  To use the
percussion channel you set the property @code{instrument} to
@code{'drums}. Because the drum-pitches themselves are similar to the
general MIDI pitches all you have to do is to insert the voices with
none of the scheme functions to get the correct MIDI output:

@example
\score @{    
    \apply #(drums->paper 'mydrums) \context Staff <
        \clef percussion
        @{ \up @}  \\
        @{ \down @}
    >
    \paper@{@}
@}
\score @{    
    \context Staff <
        \property Staff.instrument = #'drums
        \up \down
    >
    \midi@{@}
@}
@end example

@refbugs

This scheme is a temporary implementation.


@node Piano music
@section Piano music

Piano staves are two normal staves coupled with a brace.  The staves
are largely independent, but sometimes voices can cross between the
two staves.  The same notation is also used for harps and other key
instruments.  The @internalsref{PianoStaff} is especially built to
handle this cross-staffing behavior.  In this section we discuss the
@internalsref{PianoStaff} and some other pianistic peculiarities.


@menu
* Automatic staff changes::     
* Manual staff switches::       
* Pedals::                      
* Arpeggio::                    
* Staff switch lines::          
@end menu 

@refbugs

There is no support for putting chords across staves.  You can get
this result by increasing the length of the stem in the lower stave so
it reaches the stem in the upper stave, or vice versa. An example is
included with the distribution as @inputfileref{input/test,stem-cross-staff.ly}.

Dynamics are not centered, but kludges do exist. See
@inputfileref{input/template,piano-dynamics.ly}.

@cindex cross staff stem
@cindex stem, cross staff


@c fixme: should have hyperlinks as well.





@node Automatic staff changes
@subsection Automatic staff changes
@cindex Automatic staff changes

Voices can switch automatically between the top and the bottom
staff. The syntax for this is
@example
  \autochange Staff \context Voice @{ @dots{}@var{music}@dots{} @}
@end example
The two staffs of the piano staff must be named @code{up} and
@code{down}.

The autochanger switches on basis of pitch (central C is the turning
point), and it looks ahead skipping over rests to switch in
advance. Here is a practical example:
        
@lilypond[verbatim,singleline,quote]
\score { \notes \context PianoStaff <
  \context Staff = "up" {
    \autochange Staff \context Voice = VA < \relative c' {
       g4 a  b c d r4 a g } > }
  \context Staff = "down" {
       \clef bass
       s1*2
} > }
@end lilypond

@noindent
In this example, spacer rests are used to prevent the bottom staff from
terminating too soon.


@seealso

@internalsref{AutoChangeMusic}.

@refbugs

The staff switches often do not end up in optimal places. For high
quality output staff switches should be specified manually.

 

@node Manual staff switches
@subsection Manual staff switches

@cindex manual staff switches
@cindex staff switch, manual

Voices can be switched between staves manually, using the following command:
@example
  \translator Staff = @var{staffname} @var{music}
@end example

@noindent
The string @var{staffname} is the name of the staff. It switches the
current voice from its current staff to the Staff called
@var{staffname}. Typically @var{staffname} is @code{"up"} or
@code{"down"}.


@node Pedals
@subsection Pedals
@cindex Pedals

Pianos have pedals that alter the way sound are produced. Generally, a
piano has three pedals, sustain, una corda, and sostenuto.

@syntax

Piano pedal instruction can be expressed by attaching
@code{\sustainDown}, @code{\sustainUp}, @code{\unaCorda},
@code{\treCorde}, @code{\sostenutoDown} and @code{\sostenutoUp} to a
note or chord:

@lilypond[fragment,verbatim]
  c'4-\sustainDown c'4-\sustainUp
@end lilypond

What is printed can be modified by setting @code{pedal@var{X}Strings},
where @var{X} is one of the pedal types: @code{Sustain},
@code{Sostenuto} or @code{UnaCorda}.  Refer to the generated
documentation of @internalsref{SustainPedal} for more information.

Pedals can also be indicated by a sequence of brackets, by setting the 
@code{pedalSustainStyle} property to @code{bracket} objects: 

@lilypond[fragment,verbatim]
 \property Staff.pedalSustainStyle = #'bracket
 c''4-\sustainDown d''4 e''4
 a'4-\sustainUp-\sustainDown
 f'4 g'4 a'4-\sustainUp
@end lilypond

A third style of pedal notation is a mixture of text and brackets,
obtained by setting @code{pedal-type} to @code{mixed}:

@lilypond[fragment,verbatim]
 \property Staff.pedalSustainStyle = #'mixed
c''4-\sustainDown d''4 e''4
c'4-\sustainUp-\sustainDown
 f'4 g'4 a'4-\sustainUp
@end lilypond

The default `*Ped' style for sustain and damper pedals corresponds to
@code{\pedal-type = #'text}. However, @code{mixed} is the default style
for a sostenuto pedal:

@lilypond[fragment,verbatim]
c''4-\sostenutoDown d''4 e''4 c'4 f'4 g'4 a'4-\sostenutoUp
@end lilypond

For fine-tuning of the appearance of a pedal bracket, the properties
@code{edge-width}, @code{edge-height}, and @code{shorten-pair} of
@code{PianoPedalBracket} objects (, see the detailed documentation of
@internalsref{PianoPedalBracket},) can be modified.  For example, the bracket
may be extended to the end of the note head:

@lilypond[fragment,verbatim]
\property Staff.PianoPedalBracket \override
   #'shorten-pair = #'(0 . -1.0)
c''4-\sostenutoDown d''4 e''4 c'4
f'4 g'4 a'4-\sostenutoUp
@end lilypond

@node Arpeggio
@subsection Arpeggio
@cindex Arpeggio

@cindex broken arpeggio
@cindex @code{\arpeggio}

You can specify an arpeggio sign on a chord by attaching an
@code{\arpeggio} to a chord:


@lilypond[fragment,relative,verbatim]
  <<c e g c>>-\arpeggio
@end lilypond

When an arpeggio crosses staves, you attach an arpeggio to the chords
in both staves, and set
@internalsref{PianoStaff}.@code{connectArpeggios}:

@lilypond[fragment,relative,verbatim]
  \context PianoStaff <
    \property PianoStaff.connectArpeggios = ##t
    \newcontext Staff  { <<c' e g c>>-\arpeggio }
    \newcontext Staff { \clef bass  <<c,, e g>>-\arpeggio }
  >
@end lilypond

The direction of the arpeggio is sometimes denoted by adding an
arrowhead to the wiggly line.  This can be typeset by setting
@code{arpeggio-direction}:

@lilypond[fragment,relative,verbatim]
  \context Voice {
     \property Voice.Arpeggio \set #'arpeggio-direction = #1
     <<c e g c>>-\arpeggio
     \property Voice.Arpeggio \set #'arpeggio-direction = #-1
     <<c e g c>>-\arpeggio
  }
@end lilypond

A square bracket on the left indicates that the player should not
arpeggiate the chord. To draw these brackets, set the
@code{molecule-callback} property of @code{Arpeggio} or
@code{PianoStaff.Arpeggio} objects to @code{\arpeggioBracket}, and use
@code{\arpeggio} statements within the chords as before:

@lilypond[fragment,relative,verbatim]
    \property PianoStaff.Arpeggio \override
        #'molecule-callback = \arpeggioBracket
       <<c' e g c>>-\arpeggio
@end lilypond

@refcommands

@cindex @code{\arpeggioBracket}
@code{\arpeggioBracket}, 
@cindex @code{\arpeggio}
@code{\arpeggio}.

@seealso

@internalsref{ArpeggioEvent} expression lead to
@internalsref{Arpeggio} objects.  Cross staff arpeggios are
@internalsref{PianoStaff}.@internalsref{Arpeggio}.

@refbugs

It is not possible to mix connected arpeggios and unconnected
arpeggios in one @internalsref{PianoStaff} at the same time.

@node  Staff switch lines
@subsection Staff switch lines


@cindex follow voice
@cindex staff switching
@cindex cross staff

@cindex @code{followVoice}

Whenever a voice switches to another staff a line connecting the notes
can be printed automatically. This is enabled if the property
@code{PianoStaff.followVoice} is set to true:

@lilypond[fragment,relative,verbatim]
  \context PianoStaff <
    \property PianoStaff.followVoice = ##t
    \context Staff \context Voice {
      c1
      \translator Staff=two
      b2 a
    }
    \context Staff=two { \clef bass \skip 1*2 }
  >  
@end lilypond

The associated object is @internalsref{VoiceFollower}.

@refcommands

@cindex @code{\showStaffSwitch}
@code{\showStaffSwitch}, 
@cindex @code{\hideStaffSwitch}
@code{\hideStaffSwitch}.


@node Vocal music
@section Vocal music

This section discusses how to enter and print lyrics.

@menu
* Entering lyrics::             
* The Lyrics context::          
* More stanzas::                
* Ambitus::                     
@end menu

@node Entering lyrics
@subsection Entering lyrics


@cindex lyrics
@cindex @code{\lyrics}
@cindex punctuation

Lyrics are entered in a special input mode. This mode is is introduced
by the keyword @code{\lyrics}.  In this mode you can enter lyrics, with
punctuation and accents without any hassle.  Syllables are entered like
notes, but with pitches replaced by text.  For example,
@example
  \lyrics @{ Twin-4 kle4 twin- kle litt- le star2 @}
@end example

A word in Lyrics mode begins with: an alphabetic character, @code{_},
@code{?}, @code{!}, @code{:}, @code{'}, the control characters @code{^A}
through @code{^F}, @code{^Q} through @code{^W}, @code{^Y}, @code{^^},
any 8-bit character with ASCII code over 127, or a two-character
combination of a backslash followed by one of @code{`}, @code{'},
@code{"}, or @code{^}.

Subsequent characters of a word can be any character that is not a digit
and not white space.  One important consequence of this is that a word
can end with @code{@}}. The following example is usually a bug. The
syllable includes a @code{@}}, and hence the opening brace is not balanced:
@example
  \lyrics @{ twinkle@}
@end example

@cindex @code{\property}, in @code{\lyrics}
Similarly, a  period following a alphabetic sequence, is included in the
resulting string. As a consequence, spaces must be inserted around
@code{\property} commands:
@example
  \property Lyrics . LyricText \set #'font-shape = #'italic
@end example

@cindex @code{_}
@cindex spaces, in lyrics
@cindex quotes, in lyrics

Any @code{_} character which appears in an unquoted word is converted
to a space.  This provides a mechanism for introducing spaces into words
without using quotes.  Quoted words can also be used in Lyrics mode to
specify words that cannot be written with the above rules:

@example
  \lyrics @{ He said: "\"Let" my peo ple "go\"" @}
@end example

@cindex hyphens
Hyphens can be entered as ordinary hyphens at the end of a syllable, i.e.
@example
        soft- ware
@end example

These will be attached to the end of the first syllable.

Centered hyphens are entered using the special `@code{-}@code{-}' lyric
as a separate word between syllables.  The hyphen will have variable
length depending on the space between the syllables and it will be
centered between the syllables.

@cindex melisma
@cindex extender

When a lyric is sung over many notes (this is called a melisma), this is
indicated with a horizontal line centered between a syllable and the
next one. Such a line is called an extender line, and it is entered as
@code{__}.

@seealso

@internalsref{LyricEvent}, @internalsref{HyphenEvent}, and
@internalsref{ExtenderEvent}.

@refbugs

The definition of lyrics mode is too complex. 

@node The Lyrics context
@subsection  The Lyrics context

Lyrics are printed by interpreting them in @internalsref{Lyrics} context:
@example
 \context Lyrics \lyrics @dots{}
@end example

@cindex automatic syllable durations
@cindex @code{\addlyrics}
@cindex lyrics and melodies

This will place the lyrics according to the durations that were
entered. The lyrics can also be aligned under a given melody
automatically.  In this case, it is no longer necessary to enter the
correct duration for each syllable.  This is achieved by combining the
melody and the lyrics with the @code{\addlyrics} expression:
@example
\addlyrics
  \notes @dots{}
  \context Lyrics @dots{} 
@end example

@cindex staff order, with @code{\addlyrics}

Normally, this will put the lyrics below the staff. For different or
more complex orderings, the best way is to setup the hierarchy of
staves and lyrics first, e.g.
@example
\context ChoirStaff \notes <
  \newcontext Lyrics @{ s1 @}
  \newcontext Staff @{ s1 @}
  \newcontext Lyrics @{ s1 @}
  \newcontext Staff @{ s1 @}
>
@end example
and then combine the appropriate melodies and lyric lines:
@example
  \addlyrics
    \newcontext Staff @emph{the music}
    \newcontext Lyrics @emph{the lyrics}
@end example

putting both together, you would get
@example
\context ChoirStaff \notes <
  \newcontext Lyrics @dots{}
  \newcontext Staff @dots{}
  \addlyrics @dots{}
>
@end example

@cindex SATB
@cindex choral score

A complete example of a SATB score setup is in the file
@inputfileref{input/template,satb.ly}.

@seealso

@internalsref{LyricCombineMusic}, @internalsref{Lyrics}, and
@inputfileref{input/template,satb.ly}.

@refbugs

@code{\addlyrics} is not automatic enough: melismata are not detected
automatically, and melismata are not stopped when they hit a rest.  A
melisma on the last note in a melody is not printed.


@node More stanzas
@subsection More stanzas


@cindex phrasing, in lyrics

When multiple stanzas are printed underneath each other, the vertical
groups of syllables should be aligned around punctuation.  This can be
done automatically when corresponding lyric lines and melodies are
marked.

To this end, give the @internalsref{Voice} context an identity:
@example
\context Voice = duet @{
     \time 3/4
     g2 e4 a2 f4 g2.  @}
@end example

Then set the @internalsref{LyricsVoice} contexts to names starting with
that identity followed by a dash.  In the preceding example, the
@internalsref{Voice} identity is @code{duet}, so the identities of the
@internalsref{LyricsVoice}s are marked @code{duet-1} and @code{duet-2}:
@example
  \context LyricsVoice = "duet-1" @{
    Hi, my name is bert. @}
  \context LyricsVoice = "duet-2" @{
    Ooooo, ch\'e -- ri, je t'aime. @}
@end example
The convention for naming @internalsref{LyricsVoice} and
@internalsref{Voice} must also be used to get melismata correct in
conjunction with rests.

The complete example is shown here:
@lilypond[singleline,verbatim]
\score {
\addlyrics
  \notes \relative c'' \context Voice = duet { \time 3/4
     g2 e4 a2 f4 g2.  }
  \lyrics \context Lyrics <
  \context LyricsVoice = "duet-1" {
    \property LyricsVoice . stanza = "Bert"
    Hi, my name is bert.    }
  \context LyricsVoice = "duet-2" {
    \property LyricsVoice . stanza = "Ernie" 
    Ooooo, ch\'e -- ri, je t'aime. }
  >
}
@end lilypond

Stanza numbers, or the names of the singers can be added by setting
@code{LyricsVoice.Stanza} (for the first system) and
@code{LyricsVoice.stz} for the following systems.  Notice how dots are
surrounded with spaces in @code{\lyrics} mode:

@example
    \property LyricsVoice . stanza = "Bert"
    @dots{}
    \property LyricsVoice . stanza = "Ernie" 
@end example

To make empty spaces in lyrics, use @code{\skip}.



@refbugs

@cindex ambiguity

Input for lyrics introduces a syntactical ambiguity:
 
@example 
foo = bar 
@end example 

@noindent
is interpreted as assigning a string identifier @code{\foo} such that
it contains @code{"bar"}.  However, it could also be interpreted as
making or a music identifier @code{\foo} containing the syllable
`bar'.  The force the latter interpretation, use
@example
  foo = \lyrics bar4
@end example


@node Ambitus
@subsection Ambitus
@cindex ambitus

The term @emph{ambitus} denotes a range of pitches for a given voice in
a part of music.  It also may denote the pitch range that a musical
instrument is capable of playing.  Most musical instruments have their
ambitus standardized (or at least there is agreement upon the minimal
ambitus of a particular type of instrument), such that a composer or
arranger of a piece of music can easily meet the ambitus constraints of
the targeted instrument.  However, the ambitus of the human voice
depends on individual physiological state, including education and
training of the voice.  Therefore, a singer potentially has to check for
each piece of music if the ambitus of that piece meets his individual
capabilities.  This is why the ambitus of a piece may be of particular
value to vocal performers.

The ambitus is typically notated on a per-voice basis at the very
beginning of a piece, e.g. nearby the initial clef or time signature of
each staff.  The range is graphically specified by two noteheads, that
represent the minimum and maximum pitch.  Some publishers use a textual
notation: they put the range in words in front of the corresponding
staff.  LilyPond currently only supports the graphical ambitus notation.

To apply, add the @internalsref{Ambitus_engraver} to the
@internalsref{Voice} context, i.e.

@example
  \paper @{ \translator @{
      \VoiceContext
      \consists Ambitus_engraver
    @} @}
@end example

For example,

@lilypond[singleline]
upper = \notes \relative c {
  \clef "treble"
  \key c \minor
  as'' c e2 bes f cis d4 e f2 g
}
lower = \notes \relative c {
  \clef "treble"
  \key e \major
  e'4 b g a c es fis a cis b a g f e d2
}
\score {
  \context ChoirStaff {
    <
      \newcontext Staff { \upper }
      \newcontext Staff { \lower }
    >
  }
  \paper {
    \translator {
      \VoiceContext
      \consists Ambitus_engraver
    }
  }
}
@end lilypond


@seealso

@internalsref{Ambitus}, and @inputfileref{input/regression,ambitus.ly}.

@node Tablatures
@section Tablatures

Tablature notation is used for notating music for plucked string
instruments.  It notates pitches not by using note heads, but by
indicating on which string and fret a note must be played.  LilyPond
offers limited support for tablature.

@menu
* Tablatures basic::            
* Non-guitar tablatures::       
@end menu

@node Tablatures basic
@subsection Tablatures basic
@cindex Tablatures basic

The string number associated to a note is given as a backslash
followed by a number, e.g. @code{c4\3} for a C quarter on the third
string. By default, string 1 is the highest one, and the tuning
defaults to the standard guitar tuning (with 6 strings).  The notes
are printed as tablature, by using @internalsref{TabStaff} and
@internalsref{TabVoice} contexts:

@lilypond[fragment,verbatim]
\notes \context TabStaff  {
 a,4\5 c'\2 a\3 e'\1
 e\4 c'\2 a\3 e'\1
}
@end lilypond

When no string is specified, the first string that does not give a
fret number less than @code{minimumFret} is selected. The default
value for @code{minimumFret} is 0:


@example
e8 fis gis a b cis' dis' e'
\property TabStaff.minimumFret = #8
e8 fis gis a b cis' dis' e'
@end example
@lilypond[noindent]
frag = \notes {
    \key e \major
    e8 fis gis a b cis' dis' e'
    \property TabStaff.minimumFret = #8
    e8 fis gis a b cis' dis' e'
}
\score {
  \context StaffGroup <
    \context Staff { \clef "G_8" \frag }
    \context TabStaff { \frag }
  >
}
@end lilypond

@seealso

@internalsref{TabStaff}, @internalsref{TabVoice}, and
@internalsref{StringNumberEvent}.

@refbugs

Chords are not handled in a special way, and hence the automatic
string selector may easily select the same string to two notes in a
chord.


@node Non-guitar tablatures
@subsection Non-guitar tablatures
@cindex Non-guitar tablatures

You can change the number of strings, by setting the number of lines
in the @internalsref{TabStaff} (the @code{line-count} property of
@internalsref{TabStaff} can only be changed using
@code{\outputproperty}, for more information, see @ref{Tuning
objects}).

You can change the tuning of the strings. A string tuning is given as
a Scheme list with one integer number for each string, the number
being the pitch (measured in semitones relative to central C) of an
open string.  The numbers specified for @code{stringTuning} are the
numbers of semitones to subtract or add, starting the specified pitch
by default middle C, in string order. Thus, the notes are e, a, d, and
g:

@lilypond[fragment,verbatim]
  \context TabStaff <

    \outputproperty #(make-type-checker 'staff-symbol-interface)
                    #'line-count = #4
    \property TabStaff.stringTunings =  #'(-5 -10 -15 -20)
    
    \notes {
      a,4 c' a e' e c' a e'
    }
  > 
@end lilypond

It is possible to change the Scheme function to format the tablature
note text. The default is @code{fret-number-tablature-format}, which
uses the fret number. For instruments that do not use this notation,
you can create a special tablature formatting function. This function
takes three argument: string number, string tuning and note pitch.

@refbugs

Most of the guitar special effects such as bend have not been
implemented yet.



@node Chord names
@section Chord names
@cindex Chords

LilyPond has support for both printing chord names.  Chords may be
entered in musical chord notation, i.e. @code{<< .. >>}, but they can
also be entered by name. Internally, the chords are represented as a
set of pitches, so they can be transposed:


@lilypond[verbatim,singleline]
twoWays = \notes \transpose c c' {
  \chords {
    c1 f:sus4 bes/f
  }
  <<c e g>>
  <<f bes c'>>
  <<f bes d'>>
  }

\score {
   < \context ChordNames \twoWays
     \context Voice \twoWays > }
@end lilypond

This example also shows that the chord printing routines do not try to
be intelligent. The last chord (@code{f bes d}) is not interpreted as
an inversion.


@menu
* Chords mode::                 
* Printing chord names::        
@end menu


@node Chords mode
@subsection Chords mode
@cindex Chords mode

Chord mode is a mode where you can input sets of pitches using common
names.  It is introduced by the keyword @code{\chords}.
In chords mode,  a  chord is entered by the root, which is entered
like a common pitch:
@lilypond[fragment,verbatim,quote, relative=1]
\chords { es4.  d8 c2 }
@end lilypond
@cindex chord entry
@cindex chord mode

Other chords may be entered by suffixing a colon, and introducing a
modifier, and optionally, a number:
@c
@lilypond[fragment,verbatim,quote]
\chords { e1:m e1:7 e1:m7  }
@end lilypond
The first number following the root is taken to be the `type' of the
chord, thirds are added to the root until it reaches the specified
number:
@lilypond[fragment,verbatim]
 \chords { c:3 c:5 c:6 c:7 c:8 c:9 c:10 c:11 }
@end lilypond

@cindex root of chord
@cindex additions, in chords
@cindex removals, in  chords

More complex chords may also be constructed  adding separate steps
to a chord. Additions are added after the  number following
the colon, and are separated by dots:
@c
@lilypond[verbatim,fragment,quote]
  \chords { c:5.6 c:3.7.8 c:3.6.13 }
@end lilypond
Chord steps can be  altered by suffixing a @code{-} or @code{+} sign
to the number:
@lilypond[verbatim,fragment,quote]
  \chords { c:7+ c:5+.3-  c:3-.5-.7- }
@end lilypond
Removals are specified similarly, and are introduced by a caret.  They
must come after the additions:
@lilypond[verbatim,fragment]
  \chords { c^3 c:7^5 c:9^3.5 }
@end lilypond

Modifiers can be used to change pitches. The following modifiers are
supported:
@table @code
@item m
  is the minor chord. This modifier lowers the 3rd and (if present) the 7th step.
@item dim
  is the   diminished chord. This modifier lowers the 3rd, 5th and (if present)
  the 7th step.
@item aug
  is the augmented chord. This modifier raises the 5th step.
@item maj
  is the major 7th chord. This modifier raises the 7th step if present.  
@item sus
  is the suspended 4th or 2nd. This modifier removes the 3rd
step. Append either @code{2} or @code{4} to add the 2nd or 4th step to
the chord.
@end table
Modifiers can be mixed with additions:
@lilypond[verbatim,fragment]
  \chords { c:sus4 c:7sus4 c:dim7 c:m6 } 
@end lilypond

@cindex modifiers, in chords. 
@cindex @code{aug}
@cindex @code{dim}
@cindex @code{maj}
@cindex @code{sus}
@cindex @code{m}

Since an unaltered 11 does not sound good when combined with an
unaltered 13, the 11 is removed in this case (, unless it is added
explicitly):
@lilypond[fragment,verbatim]
  \chords { c:13 c:13.11 c:m13 }
@end lilypond 

@cindex @code{/}

An inversion (putting one pitch of the chord on the bottom), as well
as bass notes, can be specified by appending
@code{/}@var{pitch} to the chord:
@lilypond[fragment,verbatim,center]
   \chords { c1 c/g c/f }
@end lilypond 
@cindex @code{/+}

A bass note can be added instead of transposed out of the chord,
by using  @code{/+}@var{pitch}.

@lilypond[fragment,verbatim,center]
   \chords { c1 c/+g c/+f }
@end lilypond 

Chords is a mode similar to @code{\lyrics}, @code{\notes} etc.  Most
of the commands continue to work, for example, @code{r} and
@code{\skip} can be used to insert rests and spaces, and
@code{\property} may be used to change various settings.



@refbugs

Each step can only be present in a chord once.  The following
simply produces the augmented chord, since @code{5+} is interpreted
last:
@cindex clusters
@lilypond[verbatim,fragment]
  \chords { c:5.5-.5+ }
@end lilypond


@node Printing chord names
@subsection Printing chord names

@cindex printing chord names
@cindex chord names
@cindex chords

For displaying printed chord names, use the @internalsref{ChordNames} context.
The chords may be entered either using the notation
described above, or directly using @code{<<} and @code{>>}:

@lilypond[verbatim,singleline]
scheme = \notes {
  \chords {a1 b c} <<d' f' a'>>  <<e' g' b'>>
}
\score {
  \notes<
    \context ChordNames \scheme
    \context Staff \scheme
  >
}
@end lilypond

You can make the chord changes stand out by setting
@internalsref{ChordNames}.@code{chordChanges} to true.  This will only
display chord names when there is a change in the chords scheme and at
the start of a new line:

@lilypond[verbatim, linewidth=9cm]
scheme = \chords {
  c1:m c:m \break c:m c:m d
}
\score {
  \notes <
    \context ChordNames {
        \property ChordNames.chordChanges = ##t
        \scheme }
    \context Staff \transpose c c' \scheme
  >
}
@end lilypond

The default chord name layout is a system for Jazz music, proposed by
Klaus Ignatzek (see @ref{Literature}).  It can be tuned through the
following properties:

@table @code
@cindex chordNameExceptions
@item chordNameExceptions
This is a list that contains the chords that have special formatting.
For an example, see
@inputfileref{input/regression,chord-name-exceptions.ly}.
@cindex exceptions, chord names.


@cindex majorSevenSymbol
@item majorSevenSymbol
This property contains the markup object used for the 7th step, when
it is major. Predefined options are @code{whiteTriangleMarkup} and
@code{blackTriangleMarkup}.  See
@inputfileref{input/regression,chord-name-major7.ly} for an example.

@cindex chordNameSeparator
@item chordNameSeparator
Different parts of a chord name are normally separated by a
slash. By setting @code{chordNameSeparator}, you can specify other
separators, e.g.
@lilypond[fragment,verbatim]
\context ChordNames \chords {
      c:7sus4
      \property ChordNames.chordNameSeparator
        = \markup { \typewriter "|" }
      c:7sus4 }
@end lilypond

@cindex chordRootNamer
@item chordRootNamer
The root of a chord is usually printed as a letter with an optional
alteration. The transformation from pitch to letter is done by this
function.  Special note names (for example, the German ``H'' for a
B-chord) can be produced by storing a new function in this property.

@cindex chordNoteNamer
@item chordNoteNamer
The default is to print single pitch, e.g. the bass note, using the
@code{chordRootNamer}.  The @code{chordNoteNamer} property can be set
to a specialized function to change this behavior.  For example, the
base can be printed in lower case.

@end table


There are also two other chord name schemes implemented: an alternate
Jazz chord notation, and a systematic scheme called Banter chords. The
alternate jazz notation is also shown on the chart in @ref{Chord name
chart}.  Turning on these styles is described in the input file
@inputfileref{input/test/,chord-names-jazz.ly}.

@cindex Banter
@cindex jazz chords
@cindex chords, jazz  


@refcommands

@cindex @code{\germanChords}
@code{\germanChords}, 
@cindex @code{\semiGermanChords}
@code{\semiGermanChords}.




@seealso

@inputfileref{input/regression,chord-name-major7.ly},
@inputfileref{input/regression,chord-name-exceptions.ly},
@inputfileref{input/test,chord-names-jazz.ly},
@inputfileref{input/test,chord-names-german.ly},
@file{scm/chords-ignatzek.scm}, and @file{scm/chord-entry.scm}.


@refbugs

Chord names are determined solely from the list of pitches. Chord
inversions are not identified, and neither are added bass notes. This
may result in strange chord names when chords are entered with the
@code{<< .. >>} syntax.




@node Orchestral music
@section Orchestral music

@cindex  Writing parts

Orchestral music involves some special notation, both in the full
score and the individual parts. This section explains how to tackle
some common problems in orchestral music.



@menu
* Multiple staff contexts::     
* Rehearsal marks::             
* Bar numbers::                 
* Instrument names::            
* Transpose::                   
* Multi measure rests::         
* Automatic part combining::    
* Hiding staves::               
* Sound output for transposing instruments::  
@end menu

@node Multiple staff contexts
@subsection Multiple staff contexts

Polyphonic scores consist of many staves. These staves can be
constructed in three different ways:
@itemize @bullet
@item The group is started with a brace at the left. This is done with the
@internalsref{GrandStaff} context.
@item The group is started with a bracket. This is done with the
@internalsref{StaffGroup} context
@item The group is  started with a vertical line. This is the default
for the score.
@end itemize

@cindex Staff, multiple
@cindex bracket, vertical
@cindex brace, vertical
@cindex grand staff
@cindex staff group




@node Rehearsal marks
@subsection Rehearsal marks
@cindex Rehearsal marks
@cindex mark
@cindex @code{\mark}

To print a  rehearsal mark, use the @code{\mark} command:
@lilypond[fragment,verbatim]
\relative c'' {
  c1 \mark "A"
  c1 \mark "B"
  c1 \mark "12"
  c1 \mark "13"
  c1
}
@end lilypond

The mark is incremented automatically if you use @code{\mark
\default}. The value to use is stored in the property
@code{rehearsalMark} is used and automatically incremented.

The @code{\mark} command can also be used to put signs like coda,
segno and fermatas on a barline. Use @code{\markup} to
to access the appropriate symbol:

@lilypond[fragment,verbatim,relative=1]
  c1 \mark \markup { \musicglyph #"scripts-ufermata" }
  c1
@end lilypond

In this case, during line breaks,
marks must also be printed at the end of the line, and not at the
beginning. Use the following to force that behavior:
@example
\property Score.RehearsalMark \override
  #'break-visibility = #begin-of-line-invisible
@end example

See @inputfileref{input/test,boxed-molecule.ly} for putting boxes
around the marks.

@cindex fermatas
@cindex coda
@cindex segno
@cindex barlines, putting symbols on 

@seealso

@internalsref{MarkEvent}, @internalsref{RehearsalMark}, and
@inputfileref{input/test,boxed-molecule.ly}.


@node Bar numbers
@subsection Bar numbers


@cindex bar numbers
@cindex measure numbers
@cindex currentBarNumber

Bar numbers are printed by default at the start of the line.  The
number itself is stored in the 
@code{currentBarNumber} property,
which is normally updated automatically for every measure.

Bar numbers can be typeset at regular intervals instead of at the
beginning of each line. This is illustrated in the following example,
whose source is available as
@inputfileref{input/test,bar-number-regular-interval.ly}:

@lilypondfile[notexidoc]{bar-number-regular-interval.ly}


@seealso

@internalsref{BarNumber},
@inputfileref{input/test,bar-number-every-five-reset.ly}, and
@inputfileref{input/test,bar-number-regular-interval.ly}.

@refbugs

Bar numbers can collide with the @internalsref{StaffGroup} bracket, if
there is one at the top. To solve this, the
@code{padding} property of @internalsref{BarNumber} can be
used to position the number correctly.

@node Instrument names
@subsection Instrument names

In an orchestral score, instrument names are printed left side of the
staves.

This can be achieved by setting @internalsref{Staff}.@code{instrument}
and @internalsref{Staff}.@code{instr}. This will print a string before
the start of the staff. For the first start, @code{instrument} is
used, for the next ones @code{instr} is used:

@lilypond[verbatim,singleline]
  \property Staff.instrument = "ploink " { c''4 }  
@end lilypond

You can also use markup texts to construct more complicated instrument
names:

@lilypond[fragment,verbatim,singleline]
  \notes {
    \property Staff.instrument = \markup {
        \column << "Clarinetti"
          { "in B"
            \smaller \musicglyph #"accidentals--1"
          }
          >>
     }
     { c''1 }
  }
@end lilypond


@seealso

@internalsref{InstrumentName}.

@refbugs

When you put a name on a grand staff or piano staff the width of the
brace is not taken into account. You must add extra spaces to the end of
the name to avoid a collision.

@node Transpose
@subsection Transpose
@cindex Transpose
@cindex transposition of pitches
@cindex @code{\transpose}

A music expression can be transposed with @code{\transpose}.  The syntax
is
@example
  \transpose @var{from} @var{to} @var{musicexpr}
@end example

This means that @var{musicexpr} is transposed by the interval
between @var{from} and @var{to}.

@code{\transpose} distinguishes between enharmonic pitches: both
@code{\transpose c cis} or @code{\transpose c des} will transpose up
half a tone.  The first version will print sharps and the second
version will print flats:

@lilypond[singleline, verbatim]
mus =\notes { \key d \major cis d fis g }
\score { \notes \context Staff {
  \clef "F" \mus
  \clef "G"
  \transpose c g' \mus
  \transpose c f' \mus
}}
@end lilypond

@seealso

@internalsref{TransposedMusic}, and @internalsref{UntransposableMusic}. 

@refbugs

If you want to use both @code{\transpose} and @code{\relative}, then
you must put @code{\transpose} outside of @code{\relative}, since
@code{\relative} will have no effect music that appears inside a
@code{\transpose}.




@node  Multi measure rests
@subsection Multi measure rests
@cindex multi measure rests
@cindex Rests, multi measure

@cindex @code{R}

Multi measure rests are entered using `@code{R}'. It is specifically
meant for full bar rests and for entering parts: the rest can expand to
fill a score with rests, or it can be printed as a single multimeasure
rest. This expansion is controlled by the property
@code{Score.skipBars}. If this is set to true, Lily will not expand
empty measures, and the appropriate number is added automatically:

@lilypond[fragment,verbatim]
 \time 4/4 r1 | R1 | R1*2
 \property Score.skipBars = ##t R1*17  R1*4
@end lilypond

The @code{1} in @code{R1} is similar to the duration notation used for
notes. Hence, for time signatures other than 4/4, you must enter other
durations.  This can be done with augmentation dots or fractions:

@lilypond[fragment,verbatim]
 \property Score.skipBars = ##t
 \time 3/4
  R2. | R2.*2
 \time 13/8
 R1*13/8
 R1*13/8*12
@end lilypond

An @code{R} spanning a single measure is printed as either a whole rest
or a breve, centered in the measure regardless of the time signature.

@cindex text on multi-measure rest
@cindex script on multi-measure rest
@cindex fermata on multi-measure rest

Texts can be added to multi-measure rests by using the
@var{note}-@code{markup} syntax (see @ref{Text markup}).  In this case, the number is
replaced. If you need both texts and the number, you must add the
number by hand. A variable (@code{\fermataMarkup}) is provided for
adding fermatas:


@lilypond[verbatim,fragment]
  \time 3/4
  R2._\markup { "Ad lib" }
  R2.^\fermataMarkup
@end lilypond


@cindex whole rests for a full measure 

@seealso

@internalsref{MultiMeasureRestEvent},
@internalsref{MultiMeasureTextEvent},
@internalsref{MultiMeasureRestMusicGroup}, and
@internalsref{MultiMeasureRest}.

The layout object @internalsref{MultiMeasureRestNumber} is for the
default number, and @internalsref{MultiMeasureRestText} for user
specified texts.

@refbugs

It is not possible to use fingerings (e.g. @code{R1-4}) to put numbers
over multi-measure rests.

@cindex condensing rests

There is no way to automatically condense multiple rests into a single
multimeasure rest. Multi measure rests do not take part in rest
collisions.

Be careful when entering multimeasure rests followed by whole notes,
@example
 R1*4 cis cis 
@end example
will enter two notes lasting four measures each. When @code{skipBars}
is set, then the result will look OK, but the bar numbering will be
off.

@node Automatic part combining
@subsection Automatic part combining
@cindex automatic part combining
@cindex part combiner


Automatic part combining is used to merge two parts of music onto a
staff.  It is aimed at typesetting orchestral scores.  When the two
parts are identical for a period of time, only one is shown.  In
places where the two parts differ, they are typeset as separate
voices, and stem directions are set automatically.  Also, solo and
@emph{a due} parts are identified and can be marked.

@syntax

The syntax for part combining is

@example
  \partcombine @var{context} @var{musicexpr1} @var{musicexpr2}
@end example
where the pieces of music @var{musicexpr1} and @var{musicexpr2} will be
combined into one context of type @var{context}.  The music expressions
must be interpreted by contexts whose names should start with @code{one}
and @code{two}.

The following example demonstrates the basic functionality of the part
combiner: putting parts on one staff, and setting stem directions and
polyphony:

@lilypond[verbatim,singleline,fragment]
  \context Staff <
    \context Voice=one \partcombine Voice
      \context Thread=one \relative c'' {
        g a( b) r
      }
      \context Thread=two \relative c'' {
        g r4 r f
      }
  >
@end lilypond

The first @code{g} appears only once, although it was
specified twice (once in each part).  Stem, slur and tie directions are
set automatically, depending whether there is a solo or unisono. The
first part (with context called @code{one}) always gets up stems, and
`solo', while the second (called @code{two}) always gets down stems and
`Solo II'.

If you just want the merging parts, and not the textual markings, you
may set the property @var{soloADue} to false:

@lilypond[verbatim,singleline,fragment]
  \context Staff <
    \property Staff.soloADue = ##f
    \context Voice=one \partcombine Voice
      \context Thread=one \relative c'' {
        b4 a c g
      }
      \context Thread=two \relative c'' {
        d,2 a4 g'
      }
  >
@end lilypond

@seealso

@internalsref{PartCombineMusic},
@internalsref{Thread_devnull_engraver}, and
@internalsref{Voice_devnull_engraver} and @internalsref{A2_engraver}.

@refbugs

The syntax for naming contexts in inconsistent with the syntax for
combining stanzas.

In @code{soloADue} mode, when the two voices play the same notes on and
off, the part combiner may typeset @code{a2} more than once in a
measure:

@lilypond[fragment,singleline]
  \context Staff <
    \context Voice=one \partcombine Voice
      \context Thread=one \relative c'' {
        c b c b c a c a
      }
      \context Thread=two \relative c'' {
        b b b b f a f a
      }
  >
@end lilypond

The part combiner is slated to be rewritten [TODO: explain why].

@cindex @code{Thread_devnull_engraver}
@cindex @code{Voice_engraver}
@cindex @code{A2_engraver}

@node Hiding staves
@subsection Hiding staves

@cindex Frenched scores
@cindex Hiding staves

In orchestral scores, staff lines that only have rests are usually
removed.  This saves some space. This style is called `French Score'.
For @internalsref{Lyrics}, @internalsref{LyricsVoice},
@internalsref{ChordNames} and @internalsref{FiguredBass}, this is
switched on by default.  When these line of these contexts turn out
empty after the line-breaking process, they are removed.

For normal staves, a specialized @internalsref{Staff} context is
available, which does the same: staves containing nothing (or only
multi measure rests) are removed. The context definition is stored in
@code{\RemoveEmptyStaffContext} variable. Observe how the second staff
in this example disappears in the second line:


@lilypond[verbatim]
\score  {
  \notes \relative c' <
    \newcontext Staff { e4 f g a \break c1 }
    \newcontext Staff { c4 d e f \break R1 }
  >
  \paper {
    linewidth = 6.\cm 
    \translator { \RemoveEmptyStaffContext }
  }
}
@end lilypond


@node Sound output for transposing instruments
@subsection Sound output for transposing instruments

When you want to make a MIDI file from a score containing transposed
and untransposed instruments, you have to instruct LilyPond the pitch
offset (in semitones) for the transposed instruments. This is done
using the @code{transposing} property. It does not affect printed
output:

@cindex @code{transposing}

@example
        \property Staff.instrument = #"Cl. in B-flat"
        \property Staff.transposing = #-2
@end example


@node Ancient notation 
@section Ancient notation

@cindex Vaticana, Editio
@cindex Medicaea, Editio
@cindex hufnagel
@cindex Petrucci
@cindex mensural

@c [TODO: write more comprehensive introduction on ancient notation]

Support for ancient notation is still under heavy development.
Regardless of all of the current limitations (see the bugs section
below for details), it currently includes features for mensural
notation and Gregorian Chant notation.  There is also limited support
for figured bass notation.

Many graphical objects provide a @code{style} property, see
@ref{Ancient note heads}, @ref{Ancient accidentals}, @ref{Ancient
rests}, @ref{Ancient clefs}, @ref{Ancient flags} and @ref{Ancient time
signatures}.  By manipulating such a grob property, the typographical
appearance of the affected graphical objects can be accomodated for a
specific notation flavour without need for introducing any new
notational concept.


Other aspects of ancient notation can not that easily be expressed as
in terms of just changing a style property of a graphical object.
Therefore, some notational concepts are introduced specifically for
ancient notation, see @ref{Custodes}, @ref{Divisiones},
@ref{Ligatures}, and @ref{Figured bass}.


@menu
* Ancient note heads::          
* Ancient accidentals::         
* Ancient rests::               
* Ancient clefs::               
* Ancient flags::               
* Ancient time signatures::     
* Custodes::                    
* Divisiones::                  
* Ligatures::                   
* Figured bass::                
* Vaticana style contexts::     
@end menu

If this all is way too much of documentation for you, and you just
want to dive into typesetting without worrying too much about the
details on how to customize a context, then you may have a look at the
predefined contexts (see @ref{Vaticana style contexts}).  Use them to
set up predefined style-specific voice and staff contexts, and
directly go ahead with the note entry.

@refbugs

Ligatures need special spacing that has not yet been implemented.  As
a result, there is too much space between ligatures most of the time,
and line breaking often is unsatisfactory.  Also, lyrics do not
correctly align with ligatures.

Accidentals must not be printed within a ligature, but instead need to
be collected and printed in front of it.

Augmentum dots within ligatures are currently not handled correctly.


@node Ancient note heads
@subsection Ancient note heads

@cindex note heads

@syntax

For ancient notation, a note head style other than the @code{default}
style may be chosen.  This is accomplished by setting the @code{style}
property of the NoteHead object to the desired value (@code{baroque},
@code{neo_mensural} or @code{mensural}).  The @code{baroque} style
differs from the @code{default} style only in using a square shape for
@code{\breve} note heads.  The @code{neo_mensural} style differs from
the @code{baroque} style in that it uses rhomboidal heads for whole
notes and all smaller durations.  Stems are centered on the note
heads.  This style is in particular useful when transcribing mensural
music, e.g. for the incipit.  The @code{mensural} style finally
produces note heads that mimick the look of note heads in historic
printings of the 16th century.

The following example demonstrates the @code{neo_mensural} style:

@lilypond[fragment,singleline,verbatim]
  \property Voice.NoteHead \set #'style = #'neo_mensural
  a'\longa a'\breve a'1 a'2 a'4 a'8 a'16
@end lilypond

When typesetting a piece in Gregorian Chant notation, a Gregorian
ligature engraver will automatically select the proper note heads,
such there is no need to explicitly set the note head style.  Still,
the note head style can be set e.g. to @code{vaticana_punctum} to
produce punctum neumes.  Similarly, a mensural ligature engraver is
used to automatically assemble mensural ligatures.  See
@ref{Ligatures} for how ligature engravers work.

@seealso

@inputfileref{input/regression,note-head-style.ly} gives an overview
over all available note head styles.

@ref{Percussion staves} use note head styles of their own that are
frequently used in contemporary music notation.

@node Ancient accidentals
@subsection Ancient accidentals

@cindex accidentals

@syntax

Use the @code{style} property of grob @internalsref{Accidental} to
select ancient accidentals.  Currently supported styles are
@code{mensural}, @code{vaticana}, @code{hufnagel} and @code{medicaea}.

@lilypond[singleline,26pt]
\score {
    \notes {
        \fatText
        s
        ^\markup {
            \column <<
                "vaticana" 
                { " " \musicglyph #"accidentals-vaticana-1"
                  " " \musicglyph #"accidentals-vaticana0" }
            >>
            \column <<
                "medicaea"
                { " " \musicglyph #"accidentals-medicaea-1" }
            >>
            \column <<
                "hufnagel"
                { " " \musicglyph #"accidentals-hufnagel-1" }
            >>
            \column <<
                "mensural"
                { " " \musicglyph #"accidentals-mensural-1"
                  " " \musicglyph #"accidentals-mensural1" }
            >>
        }
    }
    \paper {
        raggedright = ##t 
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator{
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            \remove "Time_signature_engraver"
            \remove "Staff_symbol_engraver"
            minimumVerticalExtent = ##f
        }
    }
}
@end lilypond

As shown, not all accidentals are supported by each style.  When
trying to access an unsupported accidental, LilyPond will switch to a
different style, as demonstrated in
@inputfileref{input/test,ancient-accidentals.ly}.

Similarly to local accidentals, the style of the key signature can be
controlled by the @code{style} property of the
@internalsref{KeySignature} grob.

@seealso

@ref{Pitches}, @ref{Chromatic alterations} and @ref{Accidentals} give
a general introduction into the use of accidentals.  @ref{Key
signature} gives a general introduction into the use of key
signatures.


@node Ancient rests
@subsection Ancient rests

@cindex rests

@syntax

Use the @code{style} property of grob @internalsref{Rest} to select
ancient accidentals.  Currently supported styles are @code{classical},
@code{neo_mensural} and @code{mensural}.  @code{classical} differs
from the @code{default} style only in that the quarter rest looks like
a horizontally mirrored 8th rest.  The @code{neo_mensural} style suits
well for e.g. the incipit of a transcribed mensural piece of music.
The @code{mensural} style finally mimicks the appearance of rests as
in historic prints of the 16th century.

The following example demonstrates the @code{neo_mensural} style:

@lilypond[fragment,singleline,verbatim]
  \property Voice.Rest \set #'style = #'neo_mensural
  r\longa r\breve r1 r2 r4 r8 r16
@end lilypond

There are no 32th and 64th rests specifically for the mensural or
neo-mensural style.  Instead, the rests from the default style will be
taken.  See @inputfileref{input/test,rests.ly} for a chart of all
rests.

There are no rests in Gregorian Chant notation; instead, it uses
@ref{Divisiones}.

@seealso

@ref{Rests} gives a general introduction into the use of rests.


@node Ancient clefs
@subsection Ancient clefs

@cindex clefs

@syntax

LilyPond supports a variety of clefs, many of them ancient.

The following table shows all ancient clefs that are supported via the
@code{\clef} command.  Some of the clefs use the same glyph, but
differ only with respect to the line they are printed on.  In such
cases, a trailing number in the name is used to enumerate these clefs.
Still, you can manually force a clef glyph to be typeset on an
arbitrary line, as described in @ref{Clef}.  The note printed to the
right side of each clef in the example column denotes the @code{c'}
with respect to that clef.

@multitable @columnfractions  .3 .3 .3 .1

@item
@b{Glyph Name} @tab
@b{Description} @tab
@b{Supported Clefs} @tab
@b{Example}

@item
@code{clefs-neo_mensural_c} @tab
modern style mensural C clef @tab
@code{neo_mensural_c1}, @code{neo_mensural_c2},
@code{neo_mensural_c3}, @code{neo_mensural_c4} @tab
@lilypond[relative 0, notime]
\property Staff.TimeSignature \set #'transparent = ##t
\clef "neo_mensural_c2" c
@end lilypond

@item
@code{clefs-petrucci_c1}
@code{clefs-petrucci_c2}
@code{clefs-petrucci_c3}
@code{clefs-petrucci_c4}
@code{clefs-petrucci_c5}

@tab
petrucci style mensural C clefs, for use  on different  stafflines
(the examples shows the 2nd staffline C clef).

@tab
@code{petrucci_c1}
@code{petrucci_c2}
@code{petrucci_c3}
@code{petrucci_c4}
@code{petrucci_c5}

@tab
@lilypond[relative 0, notime]
\property Staff.TimeSignature \set #'transparent = ##t
\clef "petrucci_c2" c
@end lilypond

@item
@code{clefs-petrucci_f} @tab
petrucci style mensural F clef @tab
@code{petrucci_f} @tab
@lilypond[relative 0, notime]
\property Staff.TimeSignature \set #'transparent = ##t
\clef "petrucci_f" c
@end lilypond

@item
@code{clefs-petrucci_g} @tab
petrucci style mensural G clef @tab
@code{petrucci_g} @tab
@lilypond[relative 0, notime]
\property Staff.TimeSignature \set #'transparent = ##t
\clef "petrucci_g" c
@end lilypond

@item
@code{clefs-mensural_c} @tab
historic style mensural C clef @tab
@code{mensural_c1}, @code{mensural_c2}, @code{mensural_c3},
@code{mensural_c4} @tab
@lilypond[relative 0, notime]
\property Staff.TimeSignature \set #'transparent = ##t
\clef "mensural_c2" c
@end lilypond

@item
@code{clefs-mensural_f} @tab
historic style mensural F clef @tab
@code{mensural_f} @tab
@lilypond[relative 0, notime]
\property Staff.TimeSignature \set #'transparent = ##t
\clef "mensural_f" c
@end lilypond

@item
@code{clefs-mensural_g} @tab
historic style mensural G clef @tab
@code{mensural_g} @tab
@lilypond[relative 0, notime]
\property Staff.TimeSignature \set #'transparent = ##t
\clef "mensural_g" c
@end lilypond

@item
@code{clefs-vaticana_do} @tab
Editio Vaticana style do clef @tab
@code{vaticana_do1}, @code{vaticana_do2}, @code{vaticana_do3} @tab
@lilypond[relative 0, notime]
\context Staff
\outputproperty #(make-type-checker 'staff-symbol-interface) #'line-count = #4
\property Staff.TimeSignature \set #'transparent = ##t
\clef "vaticana_do2" c
@end lilypond

@item
@code{clefs-vaticana_fa} @tab
Editio Vaticana style fa clef @tab
@code{vaticana_fa1}, @code{vaticana_fa2} @tab
@lilypond[relative 0, notime]
\context Staff
\outputproperty #(make-type-checker 'staff-symbol-interface) #'line-count = #4
\property Staff.TimeSignature \set #'transparent = ##t
\clef "vaticana_fa2" c
@end lilypond

@item
@code{clefs-medicaea_do} @tab
Editio Medicaea style do clef @tab
@code{medicaea_do1}, @code{medicaea_do2}, @code{medicaea_do3} @tab
@lilypond[relative 0, notime]
\context Staff
\outputproperty #(make-type-checker 'staff-symbol-interface) #'line-count = #4
\property Staff.TimeSignature \set #'transparent = ##t
\clef "medicaea_do2" c
@end lilypond

@item
@code{clefs-medicaea_fa} @tab
Editio Medicaea style fa clef @tab
@code{medicaea_fa1}, @code{medicaea_fa2} @tab
@lilypond[relative 0, notime]
\context Staff
\outputproperty #(make-type-checker 'staff-symbol-interface) #'line-count = #4
\property Staff.TimeSignature \set #'transparent = ##t
\clef "medicaea_fa2" c
@end lilypond

@item
@code{clefs-hufnagel_do} @tab
historic style hufnagel do clef @tab
@code{hufnagel_do1}, @code{hufnagel_do2}, @code{hufnagel_do3} @tab
@lilypond[relative 0, notime]
\context Staff
\outputproperty #(make-type-checker 'staff-symbol-interface) #'line-count = #4
\property Staff.TimeSignature \set #'transparent = ##t
\clef "hufnagel_do2" c
@end lilypond

@item
@code{clefs-hufnagel_fa} @tab
historic style hufnagel fa clef @tab
@code{hufnagel_fa1}, @code{hufnagel_fa2} @tab
@lilypond[relative 0, notime]
\context Staff
\outputproperty #(make-type-checker 'staff-symbol-interface) #'line-count = #4
\property Staff.TimeSignature \set #'transparent = ##t
\clef "hufnagel_fa2" c
@end lilypond

@item
@code{clefs-hufnagel_do_fa} @tab
historic style hufnagel combined do/fa clef @tab
@code{hufnagel_do_fa} @tab
@lilypond[relative 0, notime]
\property Staff.TimeSignature \set #'transparent = ##t
\clef "hufnagel_do_fa" c
@end lilypond

@end multitable

@c --- This should go somewhere else: ---
@c @item modern style percussion clef (glyph: @code{clefs-percussion})
@c
@c Supported clefs:
@c @code{percussion}
@c
@c @lilypond{\property Staff.TimeSignature \set #'transparent = ##t \clef "percussion" c'}
@c
@c @item modern style tab clef (glyph: @code{clefs-tab})
@c
@c Supported clefs:
@c @code{tab}
@c
@c @lilypond{\context Staff \outputproperty #(make-type-checker 'staff-symbol-interface) #'line-count = #6 \property Staff.TimeSignature \set #'transparent = ##t \clef "tab" c'}

@emph{Modern style} means ``as is typeset in contemporary editions of
transcribed mensural music''.

@emph{Petrucci style} means ``inspired by printings published by the
famous engraver Petrucci (1466-1539)''.

@emph{Historic style} means ``as was typeset or written in historic
editions (other than those of Petrucci)''.

@emph{Editio XXX style} means ``as is/was printed in Editio XXX''.

Petrucci used C clefs with differently balanced left-side vertical
beams, depending on which staffline it is printed.

@seealso

For modern clefs, see @ref{Clef}.  For the percussion clef, see
@ref{Percussion staves}.  For the @code{TAB} clef, see
@ref{Tablatures}.


@node Ancient flags
@subsection Ancient flags

@cindex flags

@syntax

Use the @code{flag-style} property of grob @internalsref{Stem} to
select ancient flags.  Besides the @code{default} flag style,
currently only @code{mensural} style is supported:

@lilypond[fragment,singleline,verbatim]
  \property Voice.Stem \set #'flag-style = #'mensural
  \property Voice.Stem \set #'thickness = #1.0
  \property Voice.NoteHead \set #'style = #'mensural
  \autoBeamOff
  c'8 d'8 e'8 f'8 c'16 d'16 e'16 f'16 c'32 d'32 e'32 f'32 s8
  c''8 d''8 e''8 f''8 c''16 d''16 e''16 f''16 c''32 d''32 e''32 f''32
@end lilypond

Note that the innermost flare of each mensural flag always is
vertically aligned with a staff line.  If you do not like this
behaviour, you can set the @code{adjust-if-on-staffline} property of
grob @internalsref{Stem} to @code{##f}.  Then, the vertical position
of the end of each flare is different between notes on staff lines and
notes between staff lines:

@lilypond[fragment,singleline]
  \property Voice.Stem \set #'flag-style = #'mensural
  \property Voice.Stem \set #'thickness = #1.0
  \property Voice.Stem \set #'adjust-if-on-staffline = ##f
  \property Voice.NoteHead \set #'style = #'mensural
  \autoBeamOff
  c'8 d'8 e'8 f'8 c'16 d'16 e'16 f'16 c'32 d'32 e'32 f'32 s8
  c''8 d''8 e''8 f''8 c''16 d''16 e''16 f''16 c''32 d''32 e''32 f''32
@end lilypond

There is no particular flag style for neo-mensural notation.  Hence,
when typesetting e.g. the incipit of a transcibed piece of mensural
music, the default flag style should be used.  There are no flags in
Gregorian Chant notation.


@node Ancient time signatures
@subsection Ancient time signatures

@cindex time signatures

@syntax

There is limited support for mensural time signatures.  Currently, the
glyphs are hard-wired to particular time fractions.  In other words,
to get a particular mensural signature glyph with the @code{\time n/m}
command, @code{n} and @code{m} have to be chosen according to the
following table:

@lilypond
\score {
    \notes {
        \property Score.timing = ##f
        \property Score.barAlways = ##t
        s_\markup { "$\\backslash$time 4/4" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural4/4" }
        s
        s_\markup { "$\\backslash$time 2/2" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural2/2" }
        s
        s_\markup { "$\\backslash$time 6/4" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural6/4" }
        s
        s_\markup { "$\\backslash$time 6/8" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural6/8" }
        \break
        s_\markup { "$\\backslash$time 3/2" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural3/2" }
        s
        s_\markup { "$\\backslash$time 3/4" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural3/4" }
        s
        s_\markup { "$\\backslash$time 9/4" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural9/4" }
        s
        s_\markup { "$\\backslash$time 9/8" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural9/8" }
        \break
        s_\markup { "$\\backslash$time 4/8" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural4/8" }
        s
        s_\markup { "$\\backslash$time 2/4" }
         ^\markup { "       " \musicglyph #"timesig-neo\_mensural2/4" }
        \break
    }
    \paper {
        indent = 0.0
        raggedright = ##t
        \translator {
            \StaffContext
            \remove Staff_symbol_engraver
            \remove Clef_engraver
            \remove Time_signature_engraver
        }
    }
}
@end lilypond

Use the @code{style} property of grob @internalsref{TimeSignature} to
select ancient time signatures.  Currently supported styles are
@code{neo_mensural} and @code{mensural}.  The above table uses the
@code{neo_mensural} style.  This style is appropriate e.g. for the
incipit of transcriptions of mensural pieces.  The @code{mensural}
style mimicks the look of historical printings of the 16th century.

@inputfileref{input/test,time.ly} gives an overview over all available
ancient and modern styles.

@seealso

@ref{Time signature} gives a general introduction into the use of time
signatures.

@refbugs

Mensural signature glyphs are currently mapped to time fractions in a
hard-wired way.  This mapping is sensible, but still arbitrary: given
a mensural time signature, the time fraction represents a modern meter
that usually will be a good choice when transcribing a mensural piece
of music.  For a particular piece of mensural music, however, the
mapping may be unsatisfactory.  In particular, the mapping assumes a
fixed transcription of durations (e.g. brevis = half note in 2/2,
i.e. 4:1).  Some glyphs (such as the alternate glyph for 6/8 meter)
are currently not at all accessible through the @code{\time} command.

Mensural time signatures are supported typographically, but not yet
musically.  The internal representation of durations is currently
based on a purely binary system; a ternary division such as 1 brevis =
3 semibrevis (tempus perfectum) or 1 semibrevis = 3 minima (cum
prolatione maiori) is not correctly handled: event times in ternary
modes will be badly computed, resulting e.g. in horizontally
misaligned note heads, and bar checks are likely to erroneously fail.

The syntax and semantics of the @code{\time} command for mensural
music is subject to change.

@node Custodes
@subsection Custodes

@cindex custos
@cindex custodes

A @emph{custos} (plural: @emph{custodes}; latin word for `guard') is a
symbol that appears at the end of a staff.  It anticipates the pitch
of the first note(s) of the following line and thus helps the player
or singer to manage line breaks during performance, thus enhancing
readability of a score.

Custodes were frequently used in music notation until the 17th
century.  Nowadays, they have survived only in a few particular forms
of musical notation such as contemporary editions of Gregorian chant
like the @emph{editio vaticana}.  There are different custos glyphs
used in different flavours of notational style.

@syntax

For typesetting custodes, just put a @internalsref{Custos_engraver} into the
@internalsref{Staff} context when declaring the @code{\paper} block,
as shown in the following example:

@example
\paper @{
  \translator @{
     \StaffContext
     \consists Custos_engraver
     Custos \override #'style = #'mensural
  @}
@}
@end example

The result looks like this:

@lilypond
\score {
    \notes {
        a'1
        \property Staff.Custos \set #'style = #'mensural
        \break
        g'
    }
    \paper {
        \translator {
            \StaffContext
            \consists Custos_engraver
        }
        linewidth = 4.0\cm
    }
}
@end lilypond

The custos glyph is selected by the @code{style} property. The styles
supported are @code{vaticana}, @code{medicaea}, @code{hufnagel} and
@code{mensural}.  They are demonstrated in the following fragment:

@lilypond
\score {
    \notes {
        \fatText
        s
        ^\markup {
            \column <<
                "vaticana" 
                { " " \musicglyph #"custodes-vaticana-u0" }
            >>
            \column <<
                "medicaea"
                { " " \musicglyph #"custodes-medicaea-u0" }
            >>
            \column <<
                "hufnagel"
                { " " \musicglyph #"custodes-hufnagel-u0" }
            >>
            \column <<
                "mensural"
                { " " \musicglyph #"custodes-mensural-u0" }
            >>
        }
    }
    \paper {
        raggedright = ##t 
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator{
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            \remove "Time_signature_engraver"
            \remove "Staff_symbol_engraver"
            minimumVerticalExtent = ##f
        }
    }
}
@end lilypond

If the boolean property @code{adjust-if-on-staffline} is set to
@code{#t} (which it is by default), lily typesets slightly different
variants of the custos glyph, depending on whether the custos, is
typeset on or between stafflines.   The glyph will
optically fit well into the staff, with the appendage on the right of
the custos always ending at the same vertical position between two
stafflines regardless of the pitch.  If you set
@code{adjust-if-on-staffline} to @code{#f}, then
a compromise between both forms is  used.

Just like stems can be attached to noteheads in two directions
@emph{up} and @emph{down}, each custos glyph is available with its
appendage pointing either up or down.  If the pitch of a custos is
above a selectable position, the appendage will point downwards; if
the pitch is below this position, the appendage will point upwards.
Use property @code{neutral-position} to select this position.  By
default, it is set to @code{0}, such that the neutral position is the
center of the staff.  Use property @code{neutral-direction} to control
what happens if a custos is typeset on the neutral position itself.
By default, this property is set to @code{-1}, such that the appendage
will point downwards.  If set to @code{1}, the appendage will point
upwards.  Other values such as @code{0} are reserved for future
extensions and should not be used.

@seealso

@internalsref{Custos} and @inputfileref{input/regression,custos.ly}.


@node Divisiones
@subsection Divisiones

@cindex divisio
@cindex divisiones
@cindex finalis

A @emph{divisio} (plural: @emph{divisiones}; latin word for
`division') is a staff context symbol that is used to structure
Gregorian music into phrases and sections.  The musical meaning of
@emph{divisio minima}, @emph{divisio maior} and @emph{divisio maxima}
can be characterized as short, medium and long pause, somewhat like
@ref{Breath marks}.  The @emph{finalis} sign not only marks the end of
a chant, but is also frequently used within a single
antiphonal/responsorial chant to mark the end of each section.

@syntax

To use divisiones, include the file @code{gregorian-init.ly}.  It
contains definitions that you can apply by just inserting
@code{\divisioMinima}, @code{\divisioMaior}, @code{\divisioMaxima},
and @code{\finalis} at proper places in the input.  Some editions use
@emph{virgula} or @emph{caesura} instead of divisio minima.
Therefore, @code{gregorian-init.ly} also defines @code{\virgula} and
@code{\caesura}:

@lilypondfile[notexidoc]{divisiones.ly}

@refcommands

@cindex @code{\virgula}
@code{\virgula},
@cindex @code{\caesura}
@code{\caesura},
@cindex @code{\divisioMinima}
@code{\divisioMinima},
@cindex @code{\divisioMaior}
@code{\divisioMaior},
@cindex @code{\divisioMaxima}
@code{\divisioMaxima},
@cindex @code{\finalis}
@code{\finalis}.

@seealso

@internalsref{BreathingSign}, @internalsref{BreathingSignEvent},
@inputfileref{input/test,divisiones.ly}, and @ref{Breath marks}.

@node Ligatures
@subsection Ligatures

@cindex Ligatures

@c TODO: Should double check if I recalled things correctly when I wrote
@c down the following paragraph by heart.

In musical terminology, a ligature is a coherent graphical symbol that
represents at least two distinct notes.  Ligatures originally appeared
in the manuscripts of Gregorian chant notation roughly since the 9th
century as an allusion to the accent symbols of greek lyric poetry to
denote ascending or descending sequences of notes.  Both, the shape
and the exact meaning of ligatures changed tremendously during the
following centuries: In early notation, ligatures were used for
monophonic tunes (Gregorian chant) and very soon denoted also the way
of performance in the sense of articulation.  With upcoming
multiphony, the need for a metric system arised, since multiple voices
of a piece have to be synchronized some way.  New notation systems
were invented that used the manifold shapes of ligatures to now denote
rhythmical patterns (e.g. black mensural notation, mannered notation,
ars nova).  With the invention of the metric system of the white
mensural notation, the need for ligatures to denote such patterns
disappeared.  Nevertheless, ligatures were still in use in the
mensural system for a couple of decades until they finally disappeared
during the late 16th / early 17th century.  Still, ligatures have
survived in contemporary editions of Gregorian chant such as the
Editio Vaticana from 1905/08.

@syntax

Syntactically, ligatures are simply enclosed by @code{\[} and
@code{\]}.  Some ligature styles (such as Editio Vaticana) may need
additional input syntax specific for this particular type of ligature.
By default, the @internalsref{LigatureBracket} engraver just puts a
square bracket above the ligature:

@lilypond[singleline,verbatim]
\score {
    \notes \transpose c c' {
        \[ g c a f d' \]
        a g f
        \[ e f a g \]
    }
}
@end lilypond

To select a specific style of ligatures, a proper ligature engraver
has to be added to the @internalsref{Voice} context, as explained in
the following subsections.  Currently, only white mensural ligatures
are supported with certain limitations.  Support for Editio Vaticana
will be added in the future.

@menu
* White mensural ligatures::    
* Gregorian square neumes ligatures::  
@end menu

@node White mensural ligatures
@subsubsection White mensural ligatures

@cindex Mensural ligatures
@cindex White mensural ligatures

There is limited support for white mensural ligatures.  The
implementation is still experimental; it currently may output strange
warnings or even crash in some cases or produce weird results on more
complex ligatures.

@syntax

To engrave white mensural ligatures, in the paper block the
@internalsref{Mensural_ligature_engraver} has to be put into the
@internalsref{Voice} context, and remove the
@internalsref{Ligature_bracket_engraver}:

@example
    \paper @{
        \translator @{
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Mensural_ligature_engraver
        @}
    @}
@end example

There is no additional input language to describe the shape of a
white mensural ligature.  The shape is rather determined solely from
the pitch and duration of the enclosed notes.  While this approach may
take a new user a while to get accustomed, it has the great advantage
that the full musical information of the ligature is known internally.
This is not only required for correct MIDI output, but also allows for
automatic transcription of the ligatures.

For example,

@example
        \property Score.timing = ##f
        \property Score.defaultBarType = "empty"
        \property Voice.NoteHead \set #'style = #'neo_mensural
        \property Staff.TimeSignature \set #'style = #'neo_mensural
        \clef "petrucci_g"
        \[ g\longa c\breve a\breve f\breve d'\longa \]
        s4
        \[ e1 f1 a\breve g\longa \]
@end example
@lilypond[singleline]
\score {
    \notes \transpose c c' {
        \property Score.timing = ##f
        \property Score.defaultBarType = "empty"
        \property Voice.NoteHead \set #'style = #'neo_mensural
        \property Staff.TimeSignature \set #'style = #'neo_mensural
        \clef "petrucci_g"
        \[ g\longa c\breve a\breve f\breve d'\longa \]
        s4
        \[ e1 f1 a\breve g\longa \]
    }
    \paper {
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Mensural_ligature_engraver
        }
    }
}
@end lilypond

Without replacing @internalsref{Ligature_bracket_engraver} with
@internalsref{Mensural_ligature_engraver}, the same music transcribes
to the following:

@lilypond[singleline]
\score {
    \notes \transpose c c' {
        \property Score.timing = ##f
        \property Score.defaultBarType = "empty"
        \property Voice.NoteHead \set #'style = #'neo_mensural
        \property Staff.TimeSignature \set #'style = #'neo_mensural
        \clef "petrucci_g"
        \[ g\longa c\breve a\breve f\breve d'\longa \]
        s4
        \[ e1 f1 a\breve g\longa \]
    }
}
@end lilypond


@node Gregorian square neumes ligatures
@subsubsection Gregorian square neumes ligatures

@cindex Square neumes ligatures
@cindex Gregorian square neumes ligatures

Gregorian square neumes notation (following the style of the Editio
Vaticana) is under heavy development, but not yet really usable for
production purposes.  Core ligatures can already be typeset, but
essential issues for serious typesetting are still under development,
such as (among others) horizontal alignment of multiple ligatures,
lyrics alignment and proper accidentals handling.  Still, this section
gives a sneak preview of what Gregorian chant may look like once it
will work.

The following table contains the extended neumes table of the 2nd
volume of the Antiphonale Romanum (@emph{Liber Hymnarius}), published
1983 by the monks of Solesmes.

@multitable @columnfractions .4 .2 .2 .2

@item
@b{Neuma aut@*Neumarum Elementa} @tab
@b{Figurae@*Rectae} @tab
@b{Figurae@*Liquescentes Auctae} @tab
@b{Figurae@*Liquescentes Deminutae}

@c TODO: \paper block is identical in all of the below examples.
@c Therefore, it should somehow be included rather than duplicated all
@c the time. --jr

@c why not make identifiers in ly/engraver-init.ly? --hwn

@c Because it's just used to typeset plain notes without
@c a staff for demonstration purposes rather than something
@c special of Gregorian chant notation. --jr

@item
@code{1. Punctum}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.5cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Punctum
        \[ b \]
        \noBreak s^\markup {"a"} \noBreak

        % Punctum Inclinatum
        \[ \inclinatum b \]
        \noBreak s^\markup {"b"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=2.5cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Punctum Auctum Ascendens
        \[ \auctum \ascendens b \]
        \noBreak s^\markup {"c"} \noBreak

        % Punctum Auctum Descendens
        \[ \auctum \descendens b \]
        \noBreak s^\markup {"d"} \noBreak

        % Punctum Inclinatum Auctum
        \[ \inclinatum \auctum b \]
        \noBreak s^\markup {"e"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Punctum Inclinatum Parvum
        \[ \inclinatum \deminutum b \]
        \noBreak s^\markup {"f"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond

@item
@code{2. Virga}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Virga
        \[ \virga b \]
        \noBreak s^\markup {"g"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@tab

@item
@code{3. Apostropha vel Stropha}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Stropha
        \[ \stropha b \]
        \noBreak s^\markup {"h"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Stropha Aucta
        \[ \stropha \auctum b \]
        \noBreak s^\markup {"i"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab

@item
@code{4. Oriscus}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Oriscus
        \[ \oriscus b \]
        \noBreak s^\markup {"j"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@tab

@item
@code{5. Clivis vel Flexa}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Clivis vel Flexa
        \[ b \flexa g \]
        s^\markup {"k"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=2.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Clivis Aucta Descendens
        \[ b \flexa \auctum \descendens g \]
        \noBreak s^\markup {"l"} \noBreak

        % Clivis Aucta Ascendens
        \[ b \flexa \auctum \ascendens g \]
        \noBreak s^\markup {"m"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Cephalicus
        \[ b \flexa \deminutum g \]
        s^\markup {"n"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond

@item
@code{6. Podatus vel Pes}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Podatus vel Pes
        \[ g \pes b \]
        s^\markup {"o"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=2.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Pes Auctus Descendens
        \[ g \pes \auctum \descendens b \]
        \noBreak s^\markup {"p"} \noBreak

        % Pes Auctus Ascendens
        \[ g \pes \auctum \ascendens b \]
        \noBreak s^\markup {"q"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Epiphonus
        \[ g \pes \deminutum b \]
        s^\markup {"r"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond

@item
@code{7. Pes Quassus}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Pes Quassus
        \[ \oriscus g \pes \virga b \]
        s^\markup {"s"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Pes Quassus Auctus Descendens
        \[ \oriscus g \pes \auctum \descendens b \]
        s^\markup {"t"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab

@item
@code{8. Quilisma Pes}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Quilisma Pes
        \[ \quilisma g \pes b \]
        s^\markup {"u"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Quilisma Pes Auctus Descendens
        \[ \quilisma g \pes \auctum \descendens b \]
        s^\markup {"v"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab

@item
@code{9. Podatus Initio Debilis}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Pes Initio Debilis
        \[ \deminutum g \pes b \]
        s^\markup {"w"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Pes Auctus Descendens Initio Debilis
        \[ \deminutum g \pes \auctum \descendens b \]
        s^\markup {"x"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab

@item
@code{10. Torculus}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Torculus
        \[ a \pes b \flexa g \]
        s^\markup {"y"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Torculus Auctus Descendens
        \[ a \pes b \flexa \auctum \descendens g \]
        s^\markup {"z"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Torculus Deminutus
        \[ a \pes b \flexa \deminutum g \]
        s^\markup {"A"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond

@item
@code{11. Torculus Initio Debilis}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Torculus Initio Debilis
        \[ \deminutum a \pes b \flexa g \]
        s^\markup {"B"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Torculus Auctus Descendens Initio Debilis
        \[ \deminutum a \pes b \flexa \auctum \descendens g \]
        s^\markup {"C"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Torculus Deminutus Initio Debilis
        \[ \deminutum a \pes b \flexa \deminutum g \]
        s^\markup {"D"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond

@item
@code{12. Porrectus}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Porrectus
        \[ a \flexa g \pes b \]
        s^\markup {"E"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Porrectus Auctus Descendens
        \[ a \flexa g \pes \auctum \descendens b \]
        s^\markup {"F"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Porrectus Deminutus
        \[ a \flexa g \pes \deminutum b \]
        s^\markup {"G"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond

@item
@code{13. Climacus}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Climacus
        \[ \virga b \inclinatum a \inclinatum g \]
        s^\markup {"H"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Climacus Auctus
        \[ \virga b \inclinatum a \inclinatum \auctum g \]
        s^\markup {"I"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Climacus Deminutus
        \[ \virga b \inclinatum a \inclinatum \deminutum g \]
        s^\markup {"J"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond

@item
@code{14. Scandicus}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Scandicus
        \[ g \pes a \virga b \]
        s^\markup {"K"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Scandicus Auctus Descendens
        \[ g \pes a \pes \auctum \descendens b \]
        s^\markup {"L"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Scandicus Deminutus
        \[ g \pes a \pes \deminutum b \]
        s^\markup {"M"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond

@item
@code{15. Salicus}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Salicus
        \[ g \oriscus a \pes \virga b \]
        s^\markup {"N"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Salicus Auctus Descendens
        \[ g \oriscus a \pes \auctum \descendens b \]
        s^\markup {"O"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab

@item
@code{16. Trigonus}
@tab
@lilypond[noindent, 26pt, nofragment, linewidth=1.0cm]
\include "gregorian-init.ly"
\score {
    \notes \transpose c c' {
        % Trigonus
        \[ \stropha b \stropha b \stropha a \]
        s^\markup {"P"}
    }
    \paper {
        interscoreline = 1
        \translator {
            \ScoreContext
            \remove "Bar_number_engraver"
        }
        \translator {
            \StaffContext
            \remove "Clef_engraver"
            \remove "Key_engraver"
            StaffSymbol \set #'transparent = ##t
            \remove "Time_signature_engraver"
            \remove "Bar_engraver"
            minimumVerticalExtent = ##f
        }
        \translator {
            \VoiceContext
            \remove Ligature_bracket_engraver
            \consists Vaticana_ligature_engraver
            NoteHead \set #'style = #'vaticana_punctum
            Stem \set #'transparent = ##t
        }
    }
}
@end lilypond
@tab
@tab

@end multitable

@syntax

Unlike most other neumes notation systems, the input language for
neumes does not necessarily reflect directly the typographical
appearance, but is designed to solely focuse on musical meaning.  For
example, @code{\[ a \pes b \flexa g \]} produces a Torculus consisting
of three Punctum heads, while @code{\[ a \flexa g \pes b \]} produces
a Porrectus with a curved flexa shape and only a single Punctum head.
There is no command to explicitly typeset the curved flexa shape; the
decision of when to typeset a curved flexa shape is purely taken from
the musical input.  The idea of this approach is to separate the
musical aspects of the input from the notation style of the output.
This way, the same input can be reused to typeset the same music in a
different style of Gregorian chant notation such as Hufnagel (also
known as German gothic neumes) or Medicaea (kind of a very simple
forerunner of the Editio Vaticana).  As soon as Hufnagel ligature
engraver and Medicaea ligature engraver will have been implemented, it
will be as simple as replacing the ligature engraver in the
@internalsref{Voice} context to get the desired notation style from
the same input.

The following table shows the code fragments that produce the
ligatures in the above neumes table.  The letter in the first column
in each line of the below table indicates to which ligature in the
above table it refers.  The second column gives the name of the
ligature.  The third column shows the code fragment that produces this
ligature, using @code{g}, @code{a} and @code{b} as example pitches.

@multitable @columnfractions .1 .4 .5

@item
@b{#} @tab
@b{Name} @tab
@b{Input Language}

@item
a @tab
Punctum @tab
@code{\[ b \]}

@item
b @tab
Punctum Inclinatum @tab
@code{\[ \inclinatum b \]}

@item
c @tab
Punctum Auctum Ascendens @tab
@code{\[ \auctum \ascendens b \]}

@item
d @tab
Punctum Auctum Descendens @tab
@code{\[ \auctum \descendens b \]}

@item
e @tab
Punctum Inclinatum Auctum @tab
@code{\[ \inclinatum \auctum b \]}

@item
f @tab
Punctum Inclinatum Parvum @tab
@code{\[ \inclinatum \deminutum b \]}

@item
g @tab
Virga @tab
@code{\[ \virga b \]}

@item
h @tab
Stropha @tab
@code{\[ \stropha b \]}

@item
i @tab
Stropha Aucta @tab
@code{\[ \stropha \auctum b \]}

@item
j @tab
Oriscus @tab
@code{\[ \oriscus b \]}

@item
k @tab
Clivis vel Flexa @tab
@code{\[ b \flexa g \]}

@item
l @tab
Clivis Aucta Descendens @tab
@code{\[ b \flexa \auctum \descendens g \]}

@item
m @tab
Clivis Aucta Ascendens @tab
@code{\[ b \flexa \auctum \ascendens g \]}

@item
n @tab
Cephalicus @tab
@code{\[ b \flexa \deminutum g \]}

@item
o @tab
Podatus vel Pes @tab
@code{\[ g \pes b \]}

@item
p @tab
Pes Auctus Descendens @tab
@code{\[ g \pes \auctum \descendens b \]}

@item
q @tab
Pes Auctus Ascendens @tab
@code{\[ g \pes \auctum \ascendens b \]}

@item
r @tab
Epiphonus @tab
@code{\[ g \pes \deminutum b \]}

@item
s @tab
Pes Quassus @tab
@code{\[ \oriscus g \pes \virga b \]}

@item
t @tab
Pes Quassus Auctus Descendens @tab
@code{\[ \oriscus g \pes \auctum \descendens b \]}

@item
u @tab
Quilisma Pes @tab
@code{\[ \quilisma g \pes b \]}

@item
v @tab
Quilisma Pes Auctus Descendens @tab
@code{\[ \quilisma g \pes \auctum \descendens b \]}

@item
w @tab
Pes Initio Debilis @tab
@code{\[ \deminutum g \pes b \]}

@item
x @tab
Pes Auctus Descendens Initio Debilis @tab
@code{\[ \deminutum g \pes \auctum \descendens b \]}

@item
y @tab
Torculus @tab
@code{\[ a \pes b \flexa g \]}

@item
z @tab
Torculus Auctus Descendens @tab
@code{\[ a \pes b \flexa \auctum \descendens g \]}

@item
A @tab
Torculus Deminutus @tab
@code{\[ a \pes b \flexa \deminutum g \]}

@item
B @tab
Torculus Initio Debilis @tab
@code{\[ \deminutum a \pes b \flexa g \]}

@item
C @tab
Torculus Auctus Descendens Initio Debilis @tab
@code{\[ \deminutum a \pes b \flexa \auctum \descendens g \]}

@item
D @tab
Torculus Deminutus Initio Debilis @tab
@code{\[ \deminutum a \pes b \flexa \deminutum g \]}

@item
E @tab
Porrectus @tab
@code{\[ a \flexa g \pes b \]}

@item
F @tab
Porrectus Auctus Descendens @tab
@code{\[ a \flexa g \pes \auctum \descendens b \]}

@item
G @tab
Porrectus Deminutus @tab
@code{\[ a \flexa g \pes \deminutum b \]}

@item
H @tab
Climacus @tab
@code{\[ \virga b \inclinatum a \inclinatum g \]}

@item
I @tab
Climacus Auctus @tab
@code{\[ \virga b \inclinatum a \inclinatum \auctum g \]}

@item
J @tab
Climacus Deminutus @tab
@code{\[ \virga b \inclinatum a \inclinatum \deminutum g \]}

@item
K @tab
Scandicus @tab
@code{\[ g \pes a \virga b \]}

@item
L @tab
Scandicus Auctus Descendens @tab
@code{\[ g \pes a \pes \auctum \descendens b \]}

@item
M @tab
Scandicus Deminutus @tab
@code{\[ g \pes a \pes \deminutum b \]}

@item
N @tab
Salicus @tab
@code{\[ g \oriscus a \pes \virga b \]}

@item
O @tab
Salicus Auctus Descendens @tab
@code{\[ g \oriscus a \pes \auctum \descendens b \]}

@item
P @tab
Trigonus @tab
@code{\[ \stropha b \stropha b \stropha a \]}

@end multitable

@refcommands

The following head prefixes are supported:

@cindex @code{\virga}
@code{\virga},
@cindex @code{\stropha}
@code{\stropha},
@cindex @code{\inclinatum}
@code{\inclinatum},
@cindex @code{\auctum}
@code{\auctum},
@cindex @code{\descendens}
@code{\descendens},
@cindex @code{\ascendens}
@code{\ascendens},
@cindex @code{\oriscus}
@code{\oriscus},
@cindex @code{\quilisma}
@code{\quilisma},
@cindex @code{\deminutum}
@code{\deminutum}.

Head prefixes can be accumulated, though restrictions apply.  For
example, either @code{\descendens} or @code{\ascendens} can be applied
to a head, but not both to the same head.

@cindex @code{\pes}
@cindex @code{\flexa}
Two adjacent heads can be tied together with the @code{\pes} and
@code{\flexa} infix commands for a rising and falling line of melody,
respectively.

@refbugs

Scandicus Deminutus: Punctum Auctum Ascendens overlaps with
Semivocalis head; this looks awful.

Trigonus: apply equal spacing, regardless of pitch.

Flexa and similar figurae: the left appendix should be adjusted with
respect to the position of this head (on staffline or on staffspace)
and the vertical position of the subsequent head.

@node Figured bass
@subsection Figured bass

@cindex Basso continuo

@c TODO: musicological blurb about FB

@syntax

LilyPond has limited support for figured bass:

@lilypond[verbatim,fragment]
<
 \context Voice \notes { \clef bass dis4  c d ais}
 \context FiguredBass
   \figures {
    < 6 >4 < 7 >8 < 6+ [_!] >
    < 6 >4 <6 5 [3+] >
   }
 >
@end lilypond

The support for figured bass consists of two parts: there is an input
mode, introduced by @code{\figures}, where you can enter bass figures
as numbers, and there is a context called @internalsref{FiguredBass} that
takes care of making @internalsref{BassFigure} objects.

In figures input mode, a group of bass figures is delimited by
@code{<} and @code{>}. The duration is entered after the @code{>}:
@example
        <4 6>
@end example
@lilypond[fragment]
\context FiguredBass
\figures { <4 6> }
@end lilypond

Accidentals are added when you append @code{-}, @code{!}  and @code{+}
to the numbers:

@example
  <4- 6+ 7!>
@end example
@lilypond[fragment]
  \context FiguredBass
    \figures { <4- 6+ 7!> }
@end lilypond

Spaces or dashes may be inserted by using @code{_}. Brackets are
introduced with @code{[} and @code{]}:

@example
        < [4 6] 8 [_! 12]>
@end example
@lilypond[fragment]
 \context FiguredBass
\figures { < [4 6] 8 [_! 12]> }
@end lilypond

Although the support for figured bass may superficially resemble chord
support, it works much simpler.  The @code{\figures} mode simply
stores the numbers , and @internalsref{FiguredBass} context prints
them as entered. There is no conversion to pitches, and no
realizations of the bass are played in the MIDI file.

Internally, the code produces markup texts. You can use any of the
markup text properties to override formatting. For example, the
vertical spacing of the figures may be set with @code{baseline-skip}.

@seealso

@internalsref{BassFigureEvent} music, @internalsref{BassFigure} object, 
and @internalsref{FiguredBass} context.

@refbugs

Slash notation for alterations is not supported.


@node Vaticana style contexts
@subsection Vaticana style contexts

@cindex VaticanaVoiceContext
@cindex VaticanaStaffContext

The predefined @code{VaticanaVoiceContext} and
@code{VaticanaStaffContext} can be used to easily engrave a piece of
Gregorian Chant in the style of the Editio Vaticana.  These contexts
initialize all relevant context properties and grob properties to
proper values.  With these contexts, you can immediately go ahead
entering the chant, as the following short excerpt demonstrates:

@lilypond[raggedright,verbatim,noindent]
\include "gregorian-init.ly"
\score {
  \addlyrics
  \context VaticanaVoice {
    \property Score.BarNumber \set #'transparent = ##t
    \notes {
      \[ c'( c' \flexa a \] \[ a \flexa \deminutum g) \] f \divisioMinima
      \[ f( \pes a c' c' \pes d') \] c' \divisioMinima \break
      \[ c'( c' \flexa a \] \[ a \flexa \deminutum g) \] f \divisioMinima
    }
  }
  \context Lyrics \lyrics {
    San- ctus, San- ctus, San- ctus
  }
}
@end lilypond

@node Contemporary notation
@section Contemporary notation

In the 20th century, composers have greatly expanded the musical
vocabulary. With this expansion, many innovations in musical notation
have been tried. For a comprehensive overview, refer to @cite{Stone
1980} (see @ref{Literature}). In general, the use of new, innovative
notation makes a piece harder to understand and perform and its use
should therefore be avoided if possible.  For this reason, support for
contemporary notation in LilyPond is limited.


@menu
* Clusters::                    
* Fermatas::                    
@end menu

@node Clusters
@subsection Clusters

@cindex cluster

In musical terminology, a @emph{cluster} denotes a range of
simultaneously sounding pitches that may change over time.  The set of
available pitches to apply usually depends on the accoustic source.
Thus, in piano music, a cluster typically consists of a continous range
of the semitones as provided by the piano's fixed set of a chromatic
scale.  In choral music, each singer of the choir typically may sing an
arbitrary pitch within the cluster's range that is not bound to any
diatonic, chromatic or other scale.  In electronic music, a cluster
(theoretically) may even cover a continuous range of pitches, thus
resulting in coloured noise, such as pink noise.

Clusters can be denoted in the context of ordinary staff notation by
engraving simple geometrical shapes that replace ordinary notation of
notes.  Ordinary notes as musical events specify starting time and
duration of pitches; however, the duration of a note is expressed by the
shape of the note head rather than by the horizontal graphical extent of
the note symbol.  In contrast, the shape of a cluster geometrically
describes the development of a range of pitches (vertical extent) over
time (horizontal extent).  Still, the geometrical shape of a cluster
covers the area in wich any single pitch contained in the cluster would
be notated as an ordinary note.  From this point of view, it is
reasonable to specify a cluster as the envelope of a set of notes.

@syntax

A cluster is engraved as the envelope of a set of
cluster-notes. Cluster notes are created by applying the function
@code{notes-to-clusters} to a sequence of chords, e.g.
@c
@lilypond[relative 1,verbatim]
    \apply #notes-to-clusters {  <<c e >> <<b f'>>  }
@end lilypond

The following example (from
@inputfileref{input/regression,cluster.ly}) shows what the result
looks like:

@lilypondfile[notexidoc]{cluster.ly}

By default, @internalsref{Cluster_spanner_engraver} is in the
@internalsref{Voice} context.  This allows putting ordinary notes and
clusters together in the same staff, even simultaneously.  In such a
case no attempt is made to automatically avoid collisions between
ordinary notes and clusters.

@seealso

@internalsref{ClusterSpanner}, @internalsref{ClusterSpannerBeacon},
@inputfileref{input/regression,cluster.ly},
@internalsref{Cluster_spanner_engraver}, and @internalsref{ClusterNoteEvent}.

@refbugs

Music expressions like @code{< @{ g8 e8 @} a4 >} are not printed
accurately.  Use @code{<<g a>>8 <<e a>>8} instead.



@node Fermatas
@subsection Fermatas

@cindex fermatas



Contemporary music notation frequently uses special fermata symbols to
indicate fermatas of differing lengths.

@syntax

The following are supported

@lilypond[singleline]
\score {
  <  \addlyrics \notes {
        b'
        ^\shortfermata
        _\shortfermata
        r
        b'
        ^\fermata
        _\fermata

        r
        b'
        ^\longfermata
        _\longfermata

        r
        b'
        ^\verylongfermata
        _\verylongfermata
        r
    }
    \context Lyrics \lyrics {
      "shortfermata" "fermata"  "longfermata" "verylongfermata"
    } >
}
@end lilypond

See @ref{Articulations} for general instructions how to apply scripts
such as fermatas to a @code{\notes@{@}} block.

@node Tuning output
@section Tuning output

There are situations where default layout decisions are not
sufficient.  In this section we discuss ways to override these
defaults.

Formatting is internally done by manipulating so called objects
(graphic objects). Each object carries with it a set of properties
(object or layout properties) specific to that object.  For example, a
stem object has properties that specify its direction, length and
thickness.

The most direct way of tuning the output is by altering the values of
these properties. There are two ways of doing that: first, you can
temporarily change the definition of one type of object, thus
affecting a whole set of objects.  Second, you can select one specific
object, and set a layout property in that object.

Do not confuse layout properties with translation
properties. Translation properties always use a mixed caps style
naming, and are manipulated using @code{\property}:
@example
  \property Context.propertyName  = @var{value}
@end example
Layout properties are use Scheme style variable naming, i.e.  lower
case words separated with dashes. They are symbols, and should always
be quoted using @code{#'}.  For example, this could be an imaginary
layout property name:
@example
  #'layout-property-name
@end example

@menu
* Tuning objects ::             
* Constructing a tweak::        
* Applyoutput::                 
* Outputproperty::              
* Font selection::              
* Text markup::                 
@end menu



@node Tuning objects 
@subsection Tuning objects 

@cindex object description

The definition of an object is a list of default object
properties. For example, the definition of the Stem object (available
in @file{scm/define-grobs.scm}), includes the following definitions
for @internalsref{Stem}:

@example
        (thickness . 1.3)
        (beamed-lengths . (0.0 2.5 2.0 1.5))
        (Y-extent-callback . ,Stem::height)
        @var{...}
@end example


Adding variables on top of this existing definition overrides the
system default, and alters the resulting appearance of the layout
object.

@syntax


Changing a variable for only one object is commonly achieved with
@code{\once}:

@example
\once \property @var{context}.@var{objectname}
  \override @var{symbol} = @var{value}
@end example
Here @var{symbol} is a Scheme expression of symbol type, @var{context}
and @var{objectname} is a string and @var{value} is a Scheme expression.
This command applies a setting only during one moment in the score.

In the following example, only one @internalsref{Stem} object is
changed from its original setting:

@lilypond[verbatim, fragment, relative=1]
  c4 
  \once \property Voice.Stem \set #'thickness = #4
  c4
  c4
@end lilypond
@cindex @code{\once}

For changing more objects, the same command, without @code{\once} can
be used:
@example
\property @var{context}.@var{objectname} \override @var{symbol} = @var{value}
@end example
This command adds @code{@var{symbol} = @var{value}} to the definition
of @var{objectname} in the context @var{context}, and this definition
stays in place until it is removed.

An existing definition may be removed by the following command:
@c
@example
\property @var{context}.@var{objectname} \revert @var{symbol}
@end example
@c
All @code{\override} and @code{\revert} commands should be balanced.
The @code{\set} shorthand performs a revert followed by an override,
and is often more convenient to use

@example
\property @var{context}.@var{objectname} \set @var{symbol} = @var{value}
@end example

Some examples: 
@lilypond[verbatim,quote]
c'4 \property Voice.Stem \override #'thickness = #4.0
c'4
c'4 \property Voice.Stem \revert #'thickness
c'4
@end lilypond

The following example gives exactly the same result as the previous
one (assuming the system default for stem thickness is 1.3):
@c
@lilypond[verbatim,quote]
  c'4 \property Voice.Stem \set #'thickness = #4.0
  c'4
  c'4 \property Voice.Stem \set #'thickness = #1.3
  c'4
@end lilypond

Reverting a setting which was not set in the first place has no
effect. However, if the setting was set as a system default, this may
remove the default value, and this may give surprising results,
including crashes.  In other words, @code{\override} and
@code{\revert} must be carefully balanced.  The following are examples
of correct nesting of @code{\override}, @code{\set}, @code{\revert}:

@itemize @bullet
@item
a clumsy but correct form:
@example
  \override \revert \override \revert \override \revert
@end example

@item
shorter version of the same:
@example 
  \override \set \set  \revert
@end example

@item
a short form, using only @code{\set}. This requires you to know the
default value:
@example
  \set \set \set \set @var{to default value}
@end example

@item
if there is no default (i.e. by default, the object property is unset),
then you can use
@example
  \set \set \set \revert
@end example
@end itemize

For the digirati, the object description is an Scheme association
list. Since a Scheme list is a singly linked list, we can treat it as
a stack, and @code{\override} and @code{\revert} are push and pop
operations.  The association list is stored in a normal context
property, hence
@example
 \property Voice.NoteHead  = #'() 
@end example
will effectively erase @internalsref{NoteHead}s from the current
@internalsref{Voice}. However, this mechanism is not guaranteed to
work, and may cause crashes or other anomalous behavior.

@seealso

@internalsref{OverrideProperty}, @internalsref{RevertProperty},
@internalsref{PropertySet}, @internalsref{All-backend-properties}, and
@internalsref{All-layout-objects}.


@refbugs

The backend is not very strict in type-checking object properties.
Cyclic references in @var{value} cause hangs and/or crashes.
Similarly, reverting properties that are system defaults may also lead
to crashes.

@node Constructing a tweak
@subsection Constructing a tweak


@cindex internal documentation
@cindex finding graphical objects
@cindex graphical object descriptions 
@cindex tweaking
@cindex @code{\override}
@cindex @code{\set}
@cindex internal documentation



Three pieces of information are required to use @code{\override} and
@code{\set}: the name of the layout object, the context and the name
of the property.  We demonstrate how to glean this information from
the notation manual and the generated documentation.

The generated documentation is a set of HTML pages which should be
included if you installed a binary distribution, typically in
@file{/usr/share/doc/lilypond}.  They are also available on the web:
go to the @uref{http://lilypond.org,LilyPond website}, click
``Documentation'', and then ``Program reference'' on the side bar. It
is advisable to bookmark either the local HTML files if possible. They
will load faster than the ones on the web.  If you use the version
from the web, you must check whether the documentation matches the
program version: the documentation is generated from the definitions
that the program uses, and therefore it is strongly tied to the
LilyPond version.


@c  [TODO: revise for new site.]

Suppose we want to move the fingering indication in the fragment below:

@lilypond[relative=2,verbatim]
c-2
\stemUp
f
@end lilypond

If you visit the documentation of @code{Fingering} (in @ref{Fingering
instructions}), you will notice that there is written:

@quotation
@seealso

@internalsref{FingerEvent} and @internalsref{Fingering}.
@end quotation

@noindent
In other words, the fingerings once entered, are internally stored as
@code{FingerEvent} music objects. When printed, a @code{Fingering}
layout object is created for every @code{FingerEvent}.

The Fingering object has a number of different functions, and each of
those is captured in an interface,  when we look up
@internalsref{Fingering} in the generated documentation.



The @code{Fingering} object has a fixed size
(@internalsref{item-interface}), the symbol is a piece of text
(@internalsref{text-interface}), whose font can be set
(@internalsref{font-interface}).  It is centered horizontally
(@internalsref{self-alignment-interface}), it is placed next to other
objects (@internalsref{side-position-interface}) vertically, and its
placement is coordinated with other scripts
(@internalsref{text-script-interface}).  It also has the standard
@internalsref{grob-interface} (grob stands for Graphical object)
@cindex grob
@cindex graphical object
@cindex layout object
@cindex object, layout 
with all the variables that come with
it.  Finally, it denotes a fingering instruction, so it has
@internalsref{finger-interface}.

For the vertical placement, we have to look under
@code{side-position-interface}:
@quotation
@code{side-position-interface}

  Position a victim object (this one) next to other objects (the
  support).  In this case, the direction signifies where to put the
  victim object relative to the support (left or right, up or down?)
@end quotation

@cindex padding
@noindent
below this description, the variable @code{padding} is described as
@quotation
@table @code
@item padding
 (dimension, in staff space)

   add this much extra space between objects that are next to each
other. Default value: @code{0.6}
@end table
@end quotation

By increasing the value of @code{padding}, we can move away the
fingering.  The following command inserts 3 staff spaces of white
between the note and the fingering:
@example
\once \property Voice.Fingering \set #'padding = #3
@end example

Inserting this command before the Fingering object is created,
i.e. before @code{c2}, yields the following result:

@lilypond[relative=2,fragment,verbatim]
\once \property Voice.Fingering
  \set #'padding = #3
c-2
\stemUp
f
@end lilypond

The context name @code{Voice} in the example above can be determined
as follows. In the documentation for @internalsref{Fingering}, it says
@quotation
Fingering grobs are created by: @internalsref{Fingering_engraver}
@end quotation

Clicking @code{Fingering_engraver} shows the documentation of
the module responsible for interpreting the fingering instructions and
translating them to a @code{Fingering} object.  Such a module is called
an @emph{engraver}.  The documentation of the @code{Fingering_engraver}
says
@example
Fingering_engraver is part of contexts: Voice 
@end example
so tuning the settings for Fingering should be done with
@example
  \property Voice.Fingering \set @dots{}
@end example

Of course, the tweak may also done in a larger context than
@code{Voice}, for example, @internalsref{Staff} or
@internalsref{Score}.

The internals document also contains alphabetical lists of
@internalsref{Contexts}, @internalsref{All-layout-objects} and
@internalsref{Music-expressions}, so you can also find which objects to
tweak by browsing the internals document.


@node Applyoutput
@subsection Applyoutput

The most versatile way of tuning an object is @code{\applyoutput}. Its
syntax is
@example
\applyoutput @var{proc}
@end example

@noindent
where @var{proc} is a Scheme function, taking four arguments.

When interpreted, the function @var{proc} is called for every layout object found
in the context, with the following arguments:
@itemize @bullet
@item the layout object itself,
@item the context where the layout object was created, and
@item the context where @code{\applyoutput} is processed.
@end itemize

In addition, the cause of the layout object, i.e.  the music
expression or object that was responsible for creating it, is in the
object property @code{cause}.  For example, for a note head, this is a
@internalsref{NoteHead} event, and for a @internalsref{Stem} object,
this is a @internalsref{NoteHead} object.


@node Outputproperty
@subsection Outputproperty

@cindex @code{\outputproperty}

Another way of tuning objects is the more arcane @code{\outputproperty}
feature.  The syntax is as follows:
@example
\outputproperty @var{predicate} @var{symbol} = @var{value}
@end example
Here @code{predicate} is a Scheme function taking an object argument, and
returning a boolean.  This statement is processed by the
@code{Output_property_engraver}.  It instructs the engraver to feed all
objects that it sees to @var{predicate}. Whenever the predicate returns
true, the object property @var{symbol} will be set to @var{value}.

You will need to combine this statement with @code{\context} to select
the appropriate context to apply this to.
@inputfileref{input/regression,output-property.ly} shows an example of
the use of @code{\outputproperty}.

@refbugs

This command is slated for removal.  Please use the
@code{\applyoutput} command, see @ref{Applyoutput}.


@node Font selection
@subsection Font selection

The most common thing to change about the appearance of fonts is their
size. The font size of any context can be easily changed by setting
the @code{fontSize} property for that context.  Its value is an
integer: negative numbers make the font smaller, positive numbers
larger. An example is given below:
@c
@lilypond[fragment,relative=1,verbatim,quote]
  c4 c4 \property Voice.fontSize = #-1
  f4 g4
@end lilypond
This command will set @code{font-relative-size} (see below), and does
not change the size of variable symbols, such as beams or slurs.


One of the uses of @code{fontSize} is to get smaller symbol for cue
notes. An elaborate example of those is in
@inputfileref{input/test,cue-notes.ly}.

@cindex magnification

The size of the font may be scaled with the object property
@code{font-magnification}.  For example, @code{2.0} blows up all
letters by a factor 2 in both directions.


@cindex cue notes
@cindex font size
@cindex size
@cindex symbol size
@cindex glyph size

The font used for printing a object can be selected by setting
@code{font-name}, e.g.
@example
  \property Staff.TimeSignature
    \set #'font-name = #"cmr17"
@end example

@noindent
Any font can be used, as long as it is available to @TeX{}. Possible
fonts include foreign fonts or fonts that do not belong to the
Computer Modern font family.

Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
can also be adjusted with a more fine-grained mechanism.  By setting
the object properties described below, you can select a different font;
all three mechanisms work for every object that supports
@code{font-interface}:

@table @code
@item font-family
 is a symbol indicating the general class of the typeface.  Supported are
@code{roman} (Computer Modern), @code{braces} (for piano staff
braces), @code{music} (the standard music font, including ancient
glyphs), @code{dynamic} (for dynamic signs) and @code{typewriter}.
  
@item font-shape
  is a symbol indicating the shape of the font, there are typically several
  font shapes available for each font family. Choices are @code{italic},
  @code{caps} and @code{upright}.

@item font-series
is a  symbol indicating the series of the font. There are typically several
font series for each font family and shape. Choices are @code{medium}
and @code{bold}. 

@item font-relative-size
  is a number indicating the size relative the standard size.  For example,
  with 20pt staff height, relative size -1  corresponds to 16pt staff
  height, and relative size +1 corresponds to 23 pt staff height.

   There are small differences in design between fonts designed for
different sizes, hence @code{font-relative-size} is preferred over
@code{font-magnification} for changing font sizes.


@item font-design-size
is a number indicating  the design size of the font. 

This is a feature of the Computer Modern Font: each point size has a
slightly different design. Smaller design sizes are relatively wider,
which enhances readability.
@end table

For any of these properties, the value @code{*} (i.e. the symbol
@code{*}, entered as @code{#'*}), acts as a wildcard. This can be used
to override default setting, which are always present. For example:
@example
  \property Lyrics . LyricText \override #'font-series = #'bold
  \property Lyrics . LyricText \override #'font-family = #'typewriter
  \property Lyrics . LyricText \override #'font-shape  = #'*
@end example

@cindex @code{font-style}

@refcommands

The following commands set @code{fontSize} for the current voice.

@cindex @code{\tiny}
@code{\tiny}, 
@cindex @code{\small}
@code{\small}, 
@cindex @code{\normalsize}
@code{\normalsize}, 

@refbugs

Relative size is not linked to any real size.

There is no style sheet provided for other fonts besides the @TeX{}
family, and the style sheet cannot be modified easily.

@cindex font selection
@cindex font magnification
@cindex @code{font-interface}


@node Text markup
@subsection Text markup
@cindex text markup
@cindex markup text


@cindex typeset text

LilyPond has an internal mechanism to typeset texts. You can access it
with the keyword @code{\markup}. Within markup mode, you can enter texts
similar to lyrics: simply enter them, surrounded by spaces:
@cindex markup

@lilypond[verbatim,fragment,relative=1]
 c1^\markup { hello }
 c1_\markup { hi there }
 c1^\markup { hi \bold there, is \italic anyone home? }
@end lilypond

@cindex font switching

The markup in the example demonstrates font switching commands.  The
command @code{\bold} and @code{\italic} only apply to the first
following word; enclose a set of texts with braces to apply a command
to more words:
@example
  \markup @{ \bold @{ hi there @} @}
@end example

@noindent
For clarity, you can also do this for single arguments, e.g.
@example
  \markup @{ is \italic @{ anyone @} home @}
@end example

@cindex font size, texts

The following size commands set absolute sizes:

@cindex @code{\teeny}
@cindex @code{\tiny}
@cindex @code{\small}
@cindex @code{\large}
@cindex @code{\huge}

@table @code
@item \teeny
@item \tiny
@item \small
@item \large
@item \huge
@end table

You can also make letter larger or smaller relative to their neighbors,
with the commands @code{\larger} and @code{\smaller}.
@cindex smaller
@cindex larger

@cindex font style, for texts
@cindex @code{\bold}
@cindex @code{\dynamic}
@cindex @code{\number}
@cindex @code{\italic}

The following font change commands are defined:
@table @code
@item \dynamic
changes to the font used in dynamic signs.  This font does not
contain all characters of the alphabet, so when producing ``piu f'',
the ``piu'' should be done in a different font.


@item \number
changes to the font used in time signatures. It only contains
numbers and a few punctuation marks.
@item \italic
changes @code{font-shape} to @code{italic}.
@item \bold
changes @code{font-series} to @code{bold}.
@end table

@cindex raising text
@cindex lowering text
@cindex moving text
@cindex translating text

@cindex @code{\sub}
@cindex @code{\super}

Raising and lowering texts can be done with @code{\super} and
@code{\sub}:

@lilypond[verbatim,fragment,relative=1]
 c1^\markup { E "=" mc \super "2" }
@end lilypond

@cindex @code{\raise}

If you want to give an explicit amount for lowering or raising, use
@code{\raise}.  This command takes a Scheme valued first argument, and
a markup object as second argument:
@c
@lilypond[verbatim,fragment,relative=1,quote]
 c1^\markup { C \small \raise #1.0 \bold { "9/7+" }}
@end lilypond
The argument to @code{\raise} is the vertical displacement amount,
measured in (global) staff spaces.  @code{\raise} and @code{\super}
raise objects in relation to their surrounding markups. They cannot be
used to move a single text up or down, when it is above or below a
note, since the mechanism that positions it next to the note cancels
any vertical shift. For vertical positioning, use the @code{padding}
and/or @code{extra-offset} properties.

Other commands taking  single arguments include
@table @code

@item \bracket, \hbracket
 Bracket the argument markup with normal and horizontal brackets
respectively.

@item \musicglyph
@cindex @code{\musicglyph}
  This is converted to a musical symbol, e.g. @code{\musicglyph
#"accidentals-0"} will select the natural sign from the music font.
See @ref{The Feta font} for  a complete listing of the possible glyphs.
@item \char
This produces a single character, e.g. @code{\char #65} produces the 
letter 'A'.

@item \note  @var{log} @var{dots} @var{dir}
@cindex @code{\note}

This produces a note with a stem pointing in @var{dir} direction, with
duration log @var{log} and @var{dots} augmentation dots. The duration
log is the negative 2-logarithm of the duration denominator. For
example, a quarter note has log 2, an eighth note 3 and a breve has
log -1.

@item \hspace #@var{amount}
@cindex @code{\hspace}
This produces a invisible object taking horizontal space.
@example 
\markup @{ A \hspace #2.0 B @} 
@end example
will put extra space between A and B, on top of the space that is
normally inserted before elements on a line.

@item \fontsize #@var{size}
@cindex @code{\fontsize}
This sets the relative font size, eg.
@example
A \fontsize #2 @{ B C @} D
@end example


This will enlarge the B and the C by two steps.
@item  \translate #(cons @var{x} @var{y})
@cindex  \translate
This translates an object. Its first argument is a cons of numbers
@example
A \translate #(cons 2 -3) @{ B C @} D
@end example
This moves `B C' 2 spaces to the right, and 3 down.

@item \magnify  #@var{mag}
@cindex @code{\magnify}
This sets the font magnification for the its argument. In the following
example, the middle A will be 10% larger:
@example
A \magnify #1.1 @{ A @} A
@end example


@item \override #(@var{key} . @var{value})
@cindex @code{\override}
This overrides a  formatting property for its argument. The argument
should be a key/value pair, e.g.
@example
  m \override #'(font-family . math) m m
@end example
@end table

In markup mode you can compose expressions, similar to mathematical
expressions, XML documents and music expressions.  The braces group
notes into horizontal lines. Other types of lists also exist: you can
stack expressions grouped with @code{<<}, and @code{>>} vertically with
the command @code{\column}. Similarly, @code{\center} aligns texts by
their center lines:

@lilypond[verbatim,fragment,relative=1]
 c1^\markup { \column << a bbbb c >> }
 c1^\markup { \center << a bbbb c >> }
 c1^\markup { \line << a b c >> }
@end lilypond

The markup mechanism is extensible.  Refer to
@file{scm/new-markup.scm} for more information.



@seealso

@internalsref{Markup-functions}, and @file{scm/new-markup.scm}.

@refbugs

@cindex kerning


Text layout is ultimately done by @TeX{}, which does kerning of
letters.  LilyPond does not account for kerning, so texts will be
spaced slightly too wide.

Syntax errors for markup mode are confusing.

Markup texts cannot be used in the titling of the @code{\header}
field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
for formatting.




@node Global layout
@section Global layout

The global layout determined by three factors: the page layout, the
line breaks and the spacing. These all influence each other. The
choice of spacing determines how densely each system of music is set,
which influences where line breaks breaks are chosen, and thus
ultimately how many pages a piece of music takes. In this section, the
algorithm for spacing music is explained, and how spacing can be
tuned.

Globally spoken, this procedure happens in three steps: first,
flexible distances (``springs'') are chosen, based on durations. All
possible line breaking combination are tried, and the one with the
best results---a layout that has uniform density and requires as
little stretching or cramping as possible---is chosen. When the score
is processed by @TeX{}, each page is filled with systems, and page breaks
are chosen whenever the page gets full.



@menu
* Vertical spacing::            
* Horizontal spacing::          
* Font Size::                   
* Line breaking::               
* Page layout::                 
@end menu


@node Vertical spacing
@subsection Vertical spacing

@cindex vertical spacing
@cindex distance between staves
@cindex staff distance
@cindex between staves, distance
@cindex staffs per page
@cindex space between staves

The height of each system is determined automatically by LilyPond, to
keep systems from bumping into each other, some minimum distances are
set.  By changing these, you can put staves closer together, and thus
put more  systems onto one page.

Normally staves are stacked vertically. To make
staves maintain a distance, their vertical size is padded. This is
done with the property @code{minimumVerticalExtent}. It takes a pair
of numbers, so if you want to make it smaller from its, then you could
set
@example
  \property Staff.minimumVerticalExtent = #'(-4 . 4)
@end example
This sets the vertical size of the current staff to 4 staff-space on
either side of the center staff line.  The argument of
@code{minimumVerticalExtent} is interpreted as an interval, where the
center line is the 0, so the first number is generally negative.  The
staff can be made larger at the bottom by setting it to @code{(-6
. 4)}.

The piano staves are handled a little differently: to make cross-staff
beaming work correctly, it is necessary that the distance between staves
is fixed beforehand.  This is also done with a
@internalsref{VerticalAlignment} object, created in
@internalsref{PianoStaff}. In this object the distance between the
staves is fixed by setting @code{forced-distance}. If you want to
override this, use a @code{\translator} block as follows:
@example
  \translator @{
    \PianoStaffContext
    VerticalAlignment \override #'forced-distance = #9
  @}
@end example
This would bring the staves together at a distance of 9 staff spaces,
measured from the center line of each staff.

@seealso

Vertical alignment of staves is handled by the
@internalsref{VerticalAlignment} object.



@node Horizontal spacing
@subsection Horizontal Spacing

The spacing engine translates differences in durations into
stretchable distances (``springs'') of differing lengths. Longer
durations get more space, shorter durations get less.  The shortest
durations get a fixed amount of space (which is controlled by
@code{shortest-duration-space} in the @internalsref{SpacingSpanner} object). 
/The longer the duration, the more space it gets: doubling a
duration adds a fixed amount (this amount is controlled by
@code{spacing-increment}) of space to the note.

For example, the following piece contains lots of half, quarter and
8th notes, the eighth note is followed by 1 note head width (NHW). 
The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
@lilypond[fragment, verbatim, relative=1] c2 c4. c8 c4. c8 c4. c8 c8
c8 c4 c4 c4
@end lilypond

Normally, @code{shortest-duration-space} is set to 1.2, which is the
width of a note head, and @code{shortest-duration-space} is set to
2.0, meaning that the shortest note gets 2 NHW (2 times
@code{shortest-duration-space}) of space. For normal notes, this space
is always counted from the left edge of the symbol, so the shortest
notes are generally followed by one NHW of space.

If one would follow the above procedure exactly, then adding a single
32th note to a score that uses 8th and 16th notes, would widen up the
entire score a lot. The shortest note is no longer a 16th, but a 32nd,
thus adding 2 noteheads of space to every note. To prevent this, the
shortest duration for spacing is not the shortest note in the score,
but the most commonly found shortest note.  Notes that are even
shorter this are followed by a space that is proportonial to their
duration relative to the common shortest note.  So if we were to add
only a few 16th notes to the example above, they would be followed by
half a NHW:

@lilypond[fragment, verbatim, relative=2]
 c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4
@end lilypond

The most common shortest duration is determined as follows: in every
measure, the shortest duration is determined. The most common short
duration, is taken as the basis for the spacing, with the stipulation
that this shortest duration should always be equal to or shorter than
1/8th note. The shortest duration is printed when you run lilypond
with @code{--verbose}.  These durations may also be customized. If you
set the @code{common-shortest-duration} in
@internalsref{SpacingSpanner}, then this sets the base duration for
spacing. The maximum duration for this base (normally 1/8th), is set
through @code{base-shortest-duration}.

@cindex @code{common-shortest-duration}
@cindex @code{base-shortest-duration}
@cindex @code{stem-spacing-correction}
@cindex @code{spacing}

In the introduction it was explained that stem directions influence
spacing. This is controlled with @code{stem-spacing-correction}
property in @internalsref{NoteSpacing}, which are generated for every
@internalsref{Voice} context. The @code{StaffSpacing} object
(generated at @internalsref{Staff} context) contains the same property
for controlling the stem/barline spacing. The following example
shows these corrections, once with default settings, and once with
exaggerated corrections:

@lilypond
    \score { \notes {
      c'4 e''4 e'4 b'4 |
      b'4 e''4 b'4 e''4|
      \property Staff.NoteSpacing \override #'stem-spacing-correction
      = #1.5
      \property Staff.StaffSpacing \override #'stem-spacing-correction
      = #1.5
      c'4 e''4 e'4 b'4 |
      b'4 e''4 b'4 e''4|      
    }
    \paper { raggedright = ##t } }
@end lilypond

@cindex SpacingSpanner, overriding properties

Properties of the  @internalsref{SpacingSpanner} must be overridden
from the @code{\paper} block, since the @internalsref{SpacingSpanner} is
created before any @code{\property} statements are interpreted.
@example
\paper @{ \translator  @{
  \ScoreContext
  SpacingSpanner \override #'spacing-increment = #3.0
@} @}
@end example


@seealso

@internalsref{SpacingSpanner}, @internalsref{NoteSpacing},
@internalsref{StaffSpacing}, @internalsref{SeparationItem}, and
@internalsref{SeparatingGroupSpanner}.

@refbugs

Spacing is determined on a score wide basis. If you have a score that
changes its character (measured in durations) halfway during the
score, the part containing the longer durations will be spaced too
widely.

There is no convenient mechanism to manually override spacing.



@node Font Size
@subsection Font size
@cindex font size, setting
@cindex staff size, setting
@cindex @code{paper} file

The Feta font provides musical symbols at seven different sizes.
These fonts are 11 point, 13 point, 16 point, 20 point, 23 point, and
26 point.  The point size of a font is the height of the corresponding
staff (excluding line thicknesses).

Definitions for these sizes are the files @file{paperSZ.ly}, where
@code{SZ} is one of 11, 13, 16, 20, 23 and 26.  If you include any
of these files, the variables @code{paperEleven},
@code{paperThirteen}, @code{paperSixteen}, 
@code{paperTwenty}, @code{paperTwentythree}, and @code{paperTwentysix}
are defined respectively.  The default @code{\paper} block is also
set. These files should be imported at toplevel, i.e.
@example
        \include "paper26.ly"
        \score @{  ... @}
@end example

The default font size settings for each staff heights are generated
from the 20pt style sheet. For more details, see the file
@file{scm/font.scm}.


@node Line breaking
@subsection Line breaking

@cindex line breaks
@cindex breaking lines

Line breaks are normally computed automatically. They are chosen such
that lines look neither cramped nor loose, and that consecutive lines
have similar density.

Occasionally you might want to override the automatic breaks; you can
do this by  specifying @code{\break}. This will force a line break at
this point.  Line breaks can only occur at places where there are bar
lines.  If you want to have a line break where there is no bar line,
you can force an invisible bar line by entering @code{\bar
""}. Similarly, @code{\noBreak} forbids a line break at a 
point.


@cindex regular line breaks
@cindex four bar music. 

For linebreaks at regular intervals  use @code{\break} separated by
skips and repeated with @code{\repeat}:
@example
<  \repeat unfold 7 @{ s1 * 4 \break  @}
   @emph{the real music}
> 
@end  example

@noindent
This makes the following 28 measures (assuming 4/4 time) be broken every
4 measures.

@seealso

@internalsref{BreakEvent}.


@node Page layout
@subsection Page layout

@cindex page breaks
@cindex breaking pages

@cindex @code{indent}
@cindex @code{linewidth}

The most basic settings influencing the spacing are @code{indent} and
@code{linewidth}. They are set in the @code{\paper} block. They
control the indentation of the first line of music, and the lengths of
the lines.

If  @code{raggedright} is set to true in the @code{\paper}
block, then the lines are justified at their natural length. This
useful for short fragments, and for checking how tight the natural
spacing is.

@cindex page layout
@cindex vertical spacing

The page layout process happens outside the LilyPond formatting
engine: variables controlling page layout are passed to the output,
and are further interpreted by @code{ly2dvi}. @code{ly2dvi} responds
to the following variables in the @code{\paper} block.  The variable
@code{textheight} sets the total height of the music on each page.
The spacing between systems is controlled with @code{interscoreline},
its default is 16pt.  The distance between the score lines will
stretch in order to fill the full page @code{interscorelinefill} is
set to a positive number.  In that case @code{interscoreline}
specifies the minimum spacing.

@cindex @code{textheight}
@cindex @code{interscoreline}
@cindex @code{interscorelinefill}

If the variable @code{lastpagefill} is defined,
@c fixme: this should only be done if lastpagefill == #t 
systems are evenly distributed vertically on the last page.  This
might produce ugly results in case there are not enough systems on the
last page.  The @command{lilypond-book} command ignores
@code{lastpagefill}.  See @ref{lilypond-book manual} for more
information.

@cindex @code{lastpagefill}

Page breaks are normally computed by @TeX{}, so they are not under
direct control of LilyPond.  However, you can insert a commands into
the @file{.tex} output to instruct @TeX{} where to break pages.  This
is done by setting the @code{between-systems-strings} on the
@internalsref{NonMusicalPaperColumn} where the system is broken.
An example is shown in @inputfileref{input/regression,between-systems.ly}.
The predefined command @code{\newpage} also does this.

@cindex paper size
@cindex page size
@cindex @code{papersize}

To change the paper size, you must first set the @code{papersize} paper 
variable variable as in the example below.  Set it to
the strings @code{a4}, @code{letter}, or @code{legal}.  After this
specification, you must set the font as described above.  If you want
the default font, then use the 20 point font.

@example
        \paper@{ papersize = "a4" @}
        \include "paper16.ly"
@end example

The file @code{paper16.ly}  will now include a file named @file{a4.ly}, which
will set the paper variables @code{hsize} and @code{vsize} (used by
@code{lilypond} and @code{ly2dvi}).


@refcommands

@cindex @code{\newpage}
@code{\newpage}. 


@seealso

@ref{Invoking ly2dvi},
@inputfileref{input/regression,between-systems.ly}, and
@internalsref{NonMusicalPaperColumn}.

@refbugs

LilyPond has no concept of page layout, which makes it difficult to
reliably choose page breaks in longer pieces.




@node Sound
@section Sound
@cindex Sound

Entered music can also be converted to MIDI output.  The performance
is good enough for proof-hearing the music for errors.

Ties, dynamics and tempo changes are interpreted.  Dynamic marks,
crescendi and decrescendi translate into MIDI volume levels.  Dynamic
marks translate to a fixed fraction of the available MIDI volume
range, crescendi and decrescendi make the volume vary linearly between
their two extremities.  The fractions can be adjusted by
@code{dynamicAbsoluteVolumeFunction} in @internalsref{Voice} context.
For each type of MIDI instrument, a volume range can be defined.  This
gives a basic equalizer control, which can enhance the quality of
the MIDI output remarkably.  The equalizer can be controlled by
setting @code{instrumentEqualizer}.

@refbugs

Many musically interesting effects, such as swing, articulation,
slurring, etc., are not translated to MIDI.


@menu
* MIDI block::                  
* MIDI instrument names::       
@end menu


@node MIDI block
@subsection MIDI block
@cindex MIDI block


The MIDI block is analogous to the paper block, but it is somewhat
simpler.  The @code{\midi} block can contain:
@cindex MIDI block

@itemize @bullet
  @item a @code{\tempo} definition, and
  @item context definitions.
@end itemize

Assignments in the @code{\midi} block are not allowed.

A number followed by a period is interpreted as a real number, so
for setting the tempo for dotted notes, an extra space should be
inserted, for example:

@example
  \midi @{ \tempo 4 . = 120 @} 
@end example


@cindex context definition

Context definitions follow precisely the same syntax as within the
\paper block.  Translation modules for sound are called performers.
The contexts for MIDI output are defined in @file{ly/performer-init.ly}.


@node MIDI instrument names
@subsection MIDI instrument names

@cindex instrument names
@cindex @code{Staff.midiInstrument}
@cindex @code{Staff.instrument}

The MIDI instrument name is set by the @code{Staff.midiInstrument}
property or, if that property is not set, the @code{Staff.instrument}
property.  The instrument name should be chosen from the list in
@ref{MIDI instruments}.

@refbugs

If the selected string does not exactly match, then LilyPond uses the
default (Grand Piano). It is not possible to select an instrument by
number.