-@c -*-texinfo-*-
+@c -*- coding: latin-1; mode: texinfo; -*-
@node Changing defaults
@chapter Changing defaults
-TODO: reorganise.
+
+The purpose of LilyPond's design is to provide the finest output
+quality as a default. Nevertheless, it may happen that you need to
+change this default layout. The layout is controlled through a large
+number of proverbial ``knobs and switches.'' This chapter does not
+list each and every knob. Rather, it outlines what groups of controls
+are available and explains how to lookup which knob to use for a
+certain effect.
+
+
+@cindex Program reference
+
+The controls available for tuning are described in a separate
+document, the @internalsref{Program reference} manual. That manual
+lists all different variables, functions and options available in
+LilyPond. It is written as a HTML document, which is available
+@uref{http://lilypond.org/doc/Documentation/user/out-www/lilypond-internals/,on-line},
+but is also included with the LilyPond documentation package.
+
+There are three areas where the default settings may be changed:
+
+@itemize @bullet
+@item Output: changing the appearance of individual
+ objects. For example, changing stem directions, or the location of
+ subscripts.
+
+@item Context: changing aspects of the translation from music events to
+ notation. For example, giving each staff a separate time signature.
+
+@item Global layout: changing the appearance of the spacing, line
+ breaks and page dimensions.
+@end itemize
+
+Then, there are separate systems for typesetting text (like
+@emph{ritardando}) and selecting different fonts. This chapter also
+discusses these.
+
+Internally, LilyPond uses Scheme (a LISP dialect) to provide
+infrastructure. Overriding layout decisions in effect accesses the
+program internals, which requires Scheme input. Scheme elements are
+introduced in a @code{.ly} file with the hash mark
+@code{#}.@footnote{@ref{Scheme tutorial} contains a a short tutorial
+on entering numbers, lists, strings and symbols in Scheme.}
+
@menu
-* Scheme integration::
-* Setting variables::
-* Fine tuning layout::
-* Tuning output::
+* Interpretation contexts::
+* The \override command::
+* Fonts::
* Text markup::
* Global layout::
-* Interpretation context::
-* Output details::
+* File structure::
@end menu
+
+@node Interpretation contexts
+@section Interpretation contexts
+When music is printed, a lot of notation elements must be added to the
+input, which is often bare bones. For example, compare the input and
+output of the following example:
-@node Scheme integration
-@section Scheme integration
-
-@cindex Scheme
-@cindex GUILE
-@cindex Scheme, in-line code
-@cindex accessing Scheme
-@cindex evaluating Scheme
-@cindex LISP
+@lilypond[verbatim,relative=2,fragment]
+ cis4 cis2. g4
+@end lilypond
-LilyPond internally uses GUILE, a Scheme-interpreter, to represent
-data throughout the whole program, and glue together different program
-modules. For advanced usage, it is sometimes necessary to access and
-program the Scheme interpreter.
+The input is rather sparse, but in the output, bar lines, accidentals,
+clef, and time signature are added. LilyPond @emph{interprets} the
+input. During this step, the musical information is inspected in time
+order, similar to reading a score from left to right. While reading,
+the program remembers where measure boundaries are, and what pitches
+need explicit accidentals. This information can be presented on
+several levels. For example, the effect of an accidental is limited
+to a single stave, while a bar line must be synchronized across the
+entire score.
+
+Within LilyPond, these rules and bits of information are grouped in
+so-called Contexts. Examples of context are @context{Voice},
+@context{Staff}, and @context{Score}. They are hierarchical, for
+example, a @context{Staff} can contain many @context{Voice}s, and a
+@context{Score} can contain many @context{Staff} contexts.
+
+Each context has the responsibility for enforcing some notation rules,
+creating some notation objects and maintaining the associated
+properties. So, the synchronization of bar lines is handled at
+@context{Score} context. The @context{Voice} may introduce an
+accidentals and then the @context{Staff} context maintains the rule to
+show or suppress the accidental for the remainder of the measure.
+
+For simple scores, contexts are created implicitly, and you need not
+be aware of them. For larger pieces, such as piano music, they must be
+created explicitly to make sure that you get as many staves as you
+need, and that they are in the correct order. For typesetting pieces
+with specialized notation, it can be useful to modify existing or
+define new contexts.
+
+
+Full description of all available contexts is in the program
+reference, see
+@ifhtml
+@internalsref{Contexts}.
+@end ifhtml
+@ifnothtml
+Translation @arrow{} Context.
+@end ifnothtml
-Scheme is a full-blown programming language, from the LISP
-family. and a full discussion is outside the scope of this document.
-Interested readers are referred to the website
-@uref{http://www.schemers.org/} for more information on Scheme.
+@c [TODO: describe propagation]
-The GUILE library for extension is documented at
-@uref{http://www.gnu.org/software/guile}.
-@ifinfo
-When it is installed, the following link should take you to its manual
-@ref{(guile.info)guile}
-@end ifinfo
@menu
-* Inline Scheme::
+* Creating contexts::
+* Changing context properties on the fly::
+* Modifying context plug-ins::
+* Layout tunings within contexts::
+* Changing context default settings::
+* Defining new contexts::
@end menu
-@node Inline Scheme
-@subsection Inline Scheme
+@node Creating contexts
+@subsection Creating contexts
+
+For scores with only one voice and one staff, correct contexts are
+created automatically. For more complex scores, it is necessary to
+create them by hand. There are three commands which do this.
+
+The easiest command is @code{\new}, and it also the quickest to type.
+It is prepended to a music expression, for example
+
+@cindex @code{\new}
+@cindex new contexts
+@cindex Context, creating
-Scheme expressions can be entered in the input file by entering a
-hash-sign (@code{#}). The expression following the hash-sign is
-evaluated as Scheme. For example, the boolean value @var{true} is
-@code{#t} in Scheme, so for LilyPond @var{true} looks like @code{##t},
-and can be used in property assignments:
@example
- \set Staff.autoBeaming = ##f
+ \new @var{type} @var{music expression}
@end example
+@noindent
+where @var{type} is a context name (like @code{Staff} or
+@code{Voice}). This command creates a new context, and starts
+interpreting @var{music expression} with that.
+
+A practical application of @code{\new} is a score with many
+staves. Each part that should be on its own staff, is preceded with
+@code{\new Staff}.
+
+@lilypond[verbatim,relative=2,raggedright,fragment]
+ << \new Staff { c4 c }
+ \new Staff { d4 d }
+ >>
+@end lilypond
+
+@cindex @code{\context}
-@node Setting variables
-@section Setting variables
+Like @code{\new}, the @code{\context} command also directs a music
+expression to a context object, but gives the context an extra name. The
+syntax is
-When the music is converted from notes to print it is interpreted
-in left-to-right order. This is similar to what happens when we read
-music. During this step context-sensitive information such as the
-accidentals to print, and where bar lines must be placed, are stored in
-variables. These variables are called @emph{context properties}.
-The properties can also be manipulated from input files. Consider this input:
@example
-\set Staff.autoBeaming = ##f
-@end example
+ \context @var{type} = @var{id} @var{music}
+@end example
+
+This form will search for an existing context of type @var{type}
+called @var{id}. If that context does not exist yet, it is created.
+This is useful if the context is referred to later on. For example, when
+setting lyrics the melody is in a named context
+
+@example
+ \context Voice = "@b{tenor}" @var{music}
+@end example
@noindent
-It sets the property named @code{autoBeaming} in the current staff at
-this point in the music to @code{##f}, which means `false'. This
-property controls whether beams are printed automatically:
-@c
-@lilypond[relative=1,fragment,verbatim]
- c8 c c c
- \set Staff.autoBeaming = ##f
- c8 c c c
-@end lilypond
+so the texts can be properly aligned to its notes,
+
+@example
+\new Lyrics \lyricsto "@b{tenor}" @var{lyrics}
+@end example
@noindent
-LilyPond includes a built-in programming language, namely, a dialect
-of Scheme. The argument to @code{\set}, @code{##f}, is an
-expression in that language. The first hash-mark signals that a piece
-of Scheme code follows. The second hash character is part of the
-boolean value true (@code{#t}). Values of other types may be
-entered as follows:
-@itemize @bullet
-@item a string, enclosed in double quotes, for example,
+
+Another possibility is funneling two different music expressions into
+one context. In the following example, articulations and notes are
+entered separately,
+
+@verbatim
+music = { c4 c4 }
+arts = { s4-. s4-> }
+@end verbatim
+
+They are combined by sending both to the same @context{Voice} context,
+
+@verbatim
+ << \new Staff \context Voice = "A" \music
+ \context Voice = "A" \arts
+ >>
+@end verbatim
+@lilypond[raggedright]
+music = { c4 c4 }
+arts = { s4-. s4-> }
+ \relative c'' << \new Staff \context Voice = "A" \music
+ \context Voice = "A" \arts
+ >>
+@end lilypond
+
+With this mechanism, it is possible to define an Urtext (original
+edition), with the option put several distinct articulations on the
+same notes.
+
+@cindex @code{\context}
+@cindex creating contexts
+
+The third command for creating contexts is
@example
- \set Staff.instrument = #"French Horn"
+ \context @var{type} @var{music}
@end example
-@item a boolean: either @code{#t} or @code{#f}, for true and false
-respectively, e.g.
+
+
+@noindent
+This is similar to @code{\context} with @code{= @var{id}}, but matches
+any context of type @var{type}, regardless of its given name.
+
+This variant is used with music expressions that can be interpreted at
+several levels. For example, the @code{\applyoutput} command (see
+@ref{Running a function on all layout objects}). Without an explicit
+@code{\context}, it is usually is applied to @context{Voice}
+
@example
- \set autoBeaming = ##f
- \set Score.skipBars = ##t
+ \applyoutput #@var{function} % apply to Voice
@end example
-@item a number, such as
+To have it interpreted at the @context{Score} or @context{Staff} level use
+these forms
+
@example
- \set Score.currentBarNumber = #20
+ \context Score \applyoutput #@var{function}
+ \context Staff \applyoutput #@var{function}
@end example
-@item a symbol, which is introduced by a quote character, as in
+
+@node Changing context properties on the fly
+@subsection Changing context properties on the fly
+
+@cindex properties
+@cindex @code{\set}
+@cindex changing properties
+
+Each context can have different @emph{properties}, variables contained
+in that context. They can be changed during the interpretation step.
+This is achieved by inserting the @code{\set} command in the music,
+
+@quotation
+ @code{\set } @var{context}@code{.}@var{prop}@code{ = #}@var{value}
+@end quotation
+
+For example,
+@lilypond[verbatim,relative=2,fragment]
+ R1*2
+ \set Score.skipBars = ##t
+ R1*2
+@end lilypond
+
+This command skips measures that have no notes. The result is that
+multi rests are condensed. The value assigned is a Scheme object. In
+this case, it is @code{#t}, the boolean True value.
+
+If the @var{context} argument is left out, then the current bottom-most
+context (typically @context{ChordNames}, @context{Voice}, or
+@context{Lyrics}) is used. In this example,
+
+@lilypond[verbatim,relative=2,fragment]
+ c8 c c c
+ \set autoBeaming = ##f
+ c8 c c c
+@end lilypond
+
+@noindent
+the @var{context} argument to @code{\set} is left out, so automatic
+beaming is switched off in the current @internalsref{Voice}.
+
+Contexts are hierarchical, so if a bigger context was specified, for
+example @context{Staff}, then the change would also apply to all
+@context{Voice}s in the current stave. The change is applied
+`on-the-fly', during the music, so that the setting only affects the
+second group of eighth notes.
+
+@cindex @code{\unset}
+
+There is also an @code{\unset} command,
+@quotation
+ @code{\unset }@var{context}@code{.}@var{prop}
+@end quotation
+
+@noindent
+which removes the definition of @var{prop}. This command removes
+the definition only if it is set in @var{context}, so
+
@example
- \set Staff.crescendoSpanner = #'dashed-line
+ \set Staff.autoBeaming = ##f
@end example
-@item a pair, which is also introduced by a quote character, like in
-the following statements, which set properties to the pairs (-7.5, 6)
-and (3, 4) respectively:
+@noindent
+introduces a property setting at @code{Staff} level. The setting also
+applies to the current @code{Voice}. However,
@example
- \set Staff.minimumVerticalExtent = #'(-7.5 . 6)
- \set Staff.timeSignatureFraction = #'(3 . 4)
+ \unset Voice.autoBeaming
@end example
-@item a list, which is also introduced by a quote character. In the
-following example, the @code{breakAlignOrder} property is set to a
-list of symbols:
+@noindent
+does not have any effect. To cancel this setting, the @code{\unset}
+must be specified on the same level as the original @code{\set}. In
+other words, undoing the effect of @code{Staff.autoBeaming = ##f}
+requires
@example
- \set Score.breakAlignOrder =
- #'(left-edge time-signature key-signatures)
+ \unset Staff.autoBeaming
@end example
+Like @code{\set}, the @var{context} argument does not have to be
+specified for a bottom context, so the two statements
+
+@example
+ \set Voice.autoBeaming = ##t
+ \set autoBeaming = ##t
+@end example
+
+@noindent
+are equivalent.
-@end itemize
-There are many different properties. Not all of them are listed in
-this manual. However, the program reference lists them all in the
-section @internalsref{Context-properties}, and most properties are
-demonstrated in one of the
+@cindex \once
+Settings that should only apply to a single time-step can be entered
+with @code{\once}, for example in
+
+@lilypond[verbatim,relative=2,fragment]
+ c4
+ \once \set fontSize = #4.7
+ c4
+ c4
+@end lilypond
+
+the property @code{fontSize} is unset automatically after the second
+note.
+
+A full description of all available context properties is in the
+program reference, see
@ifhtml
-@uref{../../../input/test/out-www/collated-files.html,tips-and-tricks}
+@internalsref{Tunable-context-properties}.
@end ifhtml
@ifnothtml
-tips-and-tricks
+Translation @arrow{} Tunable context properties.
@end ifnothtml
-examples.
-@node Fine tuning layout
-@section Fine tuning layout
+@node Modifying context plug-ins
+@subsection Modifying context plug-ins
-Sometimes it is necessary to change music layout by hand. When music
-is formatted, layout objects are created for each symbol. For
-example, every clef and every note head is represented by a layout
-object. These layout objects also carry variables, which we call
-@emph{layout properties}. By changing these variables from their
-values, we can alter the look of a formatted score:
+Notation contexts (like Score and Staff) not only store properties,
+they also contain plug-ins, called ``engravers'' that create notation
+elements. For example, the Voice context contains a
+@code{Note_head_engraver} and the Staff context contains a
+@code{Key_signature_engraver}.
-@lilypond[verbatim,relative]
- c4
- \override Stem #'thickness = #3.0
- c4 c4 c4
+For a full a description of each plug-in, see
+@ifhtml
+@internalsref{Engravers}.
+@end ifhtml
+@ifnothtml
+Program reference @arrow Translation @arrow{} Engravers.
+@end ifnothtml
+Every context described in
+@ifhtml
+@internalsref{Contexts}
+@end ifhtml
+@ifnothtml
+Program reference @arrow Translation @arrow{} Context.
+@end ifnothtml
+lists the engravers used for that context.
+
+
+It can be useful to shuffle around these plug-ins. This is done by
+starting a new context, with @code{\new} or @code{\context}, and
+modifying it like this,
+
+@example
+ \new @var{context} \with @{
+ \consists @dots{}
+ \consists @dots{}
+ \remove @dots{}
+ \remove @dots{}
+ @emph{etc.}
+ @}
+ @var{..music..}
+@end example
+
+where the @dots{} should be the name of an engraver. Here is a simple
+example which removes @code{Time_signature_engraver} and
+@code{Clef_engraver} from a @code{Staff} context,
+
+@lilypond[relative=1, verbatim,fragment]
+<< \new Staff {
+ f2 g
+ }
+ \new Staff \with {
+ \remove "Time_signature_engraver"
+ \remove "Clef_engraver"
+ } {
+ f2 g2
+ }
+>>
+@end lilypond
+
+In the second stave there are no time signature or clef symbols. This
+is a rather crude method of making objects disappear since it will affect
+the entire staff. The spacing is adversely influenced too. A more
+sophisticated methods of blanking objects is shown in @ref{Common
+tweaks}.
+
+The next example shows a practical application. Bar lines and time
+signatures are normally synchronized across the score. This is done
+by the @code{Timing_engraver}. This plug-in keeps an administration of
+time signature, location within the measure, etc. By moving the
+@code{Timing_engraver} engraver from @code{Score} to @code{Staff}
+context, we can have a score where each staff has its own time
+signature.
+
+@cindex polymetric scores
+
+
+@lilypond[relative=1,raggedright,verbatim,fragment]
+\new Score \with {
+ \remove "Timing_engraver"
+} <<
+ \new Staff \with {
+ \consists "Timing_engraver"
+ } {
+ \time 3/4
+ c4 c c c c c
+ }
+ \new Staff \with {
+ \consists "Timing_engraver"
+ } {
+ \time 2/4
+ c4 c c c c c
+ }
+>>
@end lilypond
-@noindent
-In the example shown here, the layout property @code{thickness} (a
-symbol) is set to 3 in the @code{Stem} layout objects of the current
-As a result, the notes following @code{\override} have thicker
-stems.
-For the most part, a manual override is needed only on a case by
-case basis and not for all subsequent instances of the altered
-property. To accomplish this, simply prefix @code{\once} to the
-@code{\override} statement and the override will apply only once,
-immediately reverting to its default setting, i.e.
+@node Layout tunings within contexts
+@subsection Layout tunings within contexts
+
+Each context is responsible for creating certain types of graphical
+objects. The settings used for printing these objects are also stored by
+context. By changing these settings, the appearance of objects can be
+altered.
+
+The syntax for this is
@example
- \once \override Stem #'thickness = #3.0
+ \override @var{context}.@var{name}@code{ #'}@var{property} = #@var{value}
@end example
-@lilypond[relative]
+Here @var{name} is the name of a graphical object, like @code{Stem} or
+@code{NoteHead}, and @var{property} is an internal variable of the
+formatting system (`grob property' or `layout property'). The latter is a
+symbol, so it must be quoted. The subsection @ref{Constructing a
+tweak} explains what to fill in for @var{name}, @var{property}, and
+@var{value}. Here we only discuss functionality of this command.
+
+The command
+
+@verbatim
+ \override Staff.Stem #'thickness = #4.0
+@end verbatim
+
+@noindent
+makes stems thicker (the default is 1.3, with staff line thickness as a
+unit). Since the command specifies @context{Staff} as context, it only
+applies to the current staff. Other staves will keep their normal
+appearance. Here we see the command in action:
+
+@lilypond[verbatim,relative=2,fragment]
+ c4
+ \override Staff.Stem #'thickness = #4.0
c4
- \once \override Stem #'thickness = #3.0
- c4 c4 c4
+ c4
+ c4
+@end lilypond
+
+The @code{\override} command changes the definition of the @code{Stem}
+within the current @context{Staff}. After the command is interpreted
+all stems are thickened.
+
+Analogous to @code{\set}, the @var{context} argument may be left out,
+causing it to default to @context{Voice}, and adding @code{\once} applies
+the change during one timestep only
+
+@lilypond[fragment,verbatim,relative=2]
+ c4
+ \once \override Stem #'thickness = #4.0
+ c4
+ c4
+@end lilypond
+
+The @code{\override} must be done before the object is
+started. Therefore, when altering @emph{Spanner} objects, like slurs or
+beams, the @code{\override} command must be executed at the moment when
+the object is created. In this example,
+
+
+@lilypond[fragment,verbatim,relative=2]
+ \override Slur #'thickness = #3.0
+ c8[( c
+ \override Beam #'thickness = #0.6
+ c8 c])
@end lilypond
@noindent
+the slur is fatter but the beam is not. This is because the command for
+@code{Beam} comes after the Beam is started. Therefore it has no effect.
+
+Analogous to @code{\unset}, the @code{\revert} command for a context
+undoes a @code{\override} command; like with @code{\unset}, it only
+affects settings that were made in the same context. In other words, the
+@code{\revert} in the next example does not do anything.
+
+@verbatim
+ \override Voice.Stem #'thickness = #4.0
+ \revert Staff.Stem #'thickness
+@end verbatim
+
+
+
+
+@seealso
+
+Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
+@internalsref{PropertySet}, @internalsref{All-backend-properties}, and
+@internalsref{All-layout-objects}.
+
+
+@refbugs
+
+The back-end is not very strict in type-checking object properties.
+Cyclic references in Scheme values for properties can cause hangs
+or crashes, or both.
+
+
+@node Changing context default settings
+@subsection Changing context default settings
+
+The adjustments of the previous subsections (@ref{Changing context
+properties on the fly}, @ref{Modifying context plug-ins} and
+@ref{Layout tunings within contexts}) can also be entered separate
+from the music, in the @code{\layout} block,
+
+@example
+\layout @{
+ @dots{}
+ \context @{
+ \Staff
+
+ \set fontSize = #-2
+ \override Stem #'thickness = #4.0
+ \remove "Time_signature_engraver"
+ @}
+@}
+@end example
+
+Here
+@example
+ \Staff
+@end example
+
+@noindent
+takes the existing definition for context @context{Staff} from the
+identifier @code{\Staff}.
+
+The statements
+@example
+ \set fontSize = #-2
+ \override Stem #'thickness = #4.0
+ \remove "Time_signature_engraver"
+@end example
+
+@noindent
+affect all staves in the score.
+
+Other contexts can be modified analogously.
+
+The @code{\set} keyword is optional within the @code{\layout} block, so
+
+@example
+\context @{
+ @dots{}
+ fontSize = #-2
+@}
+@end example
+
+@noindent
+will also work.
+
+
+
+@refbugs
+
+It is not possible to collect context changes in a variable, and apply
+them to one @code{\context} definition by referring to that variable.
+
+
+@node Defining new contexts
+@subsection Defining new contexts
+
+Specific contexts, like @context{Staff} and @code{Voice}, are made of
+simple building blocks, and it is possible to compose engraver
+plug-ins in different combinations, thereby creating new types of
+contexts.
+
+The next example shows how to build a different type of
+@context{Voice} context from scratch. It will be similar to
+@code{Voice}, but print centered slash noteheads only. It can be used
+to indicate improvisation in Jazz pieces,
+
+@lilypond[raggedright]
+ \layout { \context {
+ \name ImproVoice
+ \type "Engraver_group_engraver"
+ \consists "Note_heads_engraver"
+ \consists "Text_engraver"
+ \consists Pitch_squash_engraver
+ squashedPosition = #0
+ \override NoteHead #'style = #'slash
+ \override Stem #'transparent = ##t
+ \alias Voice
+ }
+ \context { \Staff
+ \accepts "ImproVoice"
+ }}
+
+
+\relative c'' {
+ a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
+ c4 c^"undress" c_"while playing :)" c }
+ a1
+}
+@end lilypond
+
+
+These settings are again done within a @code{\context} block inside a
+@code{\layout} block,
+
+@example
+ \layout @{
+ \context @{
+ @dots{}
+ @}
+ @}
+@end example
+
+In the following discussion, the example input shown should go on the
+@dots{} in the previous fragment.
+
+First, name the context gets a name. Instead of @context{Voice} it
+will be called @context{ImproVoice},
+
+@verbatim
+ \name ImproVoice
+@end verbatim
+
+Since it is similar to the @context{Voice}, we want commands that work
+on (existing) @context{Voice}s to remain working. This is achieved by
+giving the new context an alias @context{Voice},
+
+@verbatim
+ \alias Voice
+@end verbatim
+
+The context will print notes, and instructive texts
+
+@verbatim
+ \consists Note_heads_engraver
+ \consists Text_engraver
+@end verbatim
+
+but only on the center line,
+
+@verbatim
+ \consists Pitch_squash_engraver
+ squashedPosition = #0
+@end verbatim
+
+The @internalsref{Pitch_squash_engraver} modifies note heads (created
+by @internalsref{Note_heads_engraver}) and sets their vertical
+position to the value of @code{squashedPosition}, in this case
+@code{0}, the center line.
+
+The notes look like a slash, without a stem,
+
+@verbatim
+ \override NoteHead #'style = #'slash
+ \override Stem #'transparent = ##t
+@end verbatim
+
+
+All these plug-ins have to cooperate, and this is achieved with a
+special plug-in, which must be marked with the keyword @code{\type}.
+This should always be @internalsref{Engraver_group_engraver},
+
+@example
+ \type "Engraver_group_engraver"
+@end example
+
+Putting together, we get
+
+@verbatim
+ \context {
+ \name ImproVoice
+ \type "Engraver_group_engraver"
+ \consists "Note_heads_engraver"
+ \consists "Text_engraver"
+ \consists Pitch_squash_engraver
+ squashedPosition = #0
+ \override NoteHead #'style = #'slash
+ \override Stem #'transparent = ##t
+ \alias Voice
+ }
+@end verbatim
+
+Contexts form hierarchies. We want to hang the @context{ImproVoice}
+under @context{Staff}, just like normal @code{Voice}s. Therefore, we
+modify the @code{Staff} definition with the @code{\accepts}
+command,@footnote{The opposite of @code{\accepts} is @code{\denies},
+which is sometimes when reusing existing context definitions. }
+
+
+
+@verbatim
+ \context {
+ \Staff
+ \accepts ImproVoice
+ }
+@end verbatim
+
+Putting both into a @code{\layout} block, like
+
+@example
+ \layout @{
+ \context @{
+ \name ImproVoice
+ @dots{}
+ @}
+ \context @{
+ \Staff
+ \accepts "ImproVoice"
+ @}
+@}
+@end example
+
+Then the output at the start of this subsection can be entered as
+
+@verbatim
+\relative c'' {
+ a4 d8 bes8
+ \new ImproVoice {
+ c4^"ad lib" c
+ c4 c^"undress"
+ c c_"while playing :)"
+ }
+ a1
+}
+@end verbatim
+
+
+
+
+@node The \override command
+@section The \override command
+
+In the previous section, we have already touched on a command that
+changes layout details, the @code{\override} command. In this section,
+we will look at in more detail how to use the command in practice.
+First, we will give a a few versatile commands, which are sufficient
+for many situations. The next section will discuss general use of
+@code{\override}.
+
+
+@menu
+* Common tweaks::
+* Constructing a tweak::
+* Navigating the program reference::
+* Layout interfaces::
+* Determining the grob property::
+* Difficult tweaks::
+@end menu
+
+
+
+@node Common tweaks
+@subsection Common tweaks
+
Some overrides are so common that predefined commands are provided as
-a short cut. For example, @code{\slurUp} and @code{\stemDown}. These
+a short-cut, for example, @code{\slurUp} and @code{\stemDown}. These
commands are described in
@ifhtml
the
The exact tuning possibilities for each type of layout object are
documented in the program reference of the respective
object. However, many layout objects share properties, which can be
-used to apply generic tweaks. We mention a couple of these:
+used to apply generic tweaks. We mention a few of these:
@itemize @bullet
@item The @code{extra-offset} property, which
@cindex setting object properties
-@lilypond[relative=1,verbatim]
+@lilypond[fragment,relative=1,verbatim]
\stemUp
f-5
\once \override Fingering
@cindex transparent objects
@cindex removing objects
+@cindex hiding objects
@cindex invisible objects
The following example demonstrates how to connect different voices
using ties. Normally, ties only connect two notes in the same
-voice. By introducing a tie in a different voice, and blanking a stem
-in that voice, the tie appears to cross voices:
+voice. By introducing a tie in a different voice,
-@lilypond[fragment,relative=1,verbatim]
- c4 << {
+@lilypond[fragment,relative=2]
+ << {
+ b8~ b8\noBeam
+ } \\ {
+ b[ g8]
+ } >>
+@end lilypond
+
+@noindent
+and blanking the first up-stem in that voice, the tie appears to cross
+voices:
+
+@lilypond[fragment,relative=2,verbatim]
+ << {
\once \override Stem #'transparent = ##t
- b8~ b8
+ b8~ b8\noBeam
} \\ {
b[ g8]
} >>
example; a more elaborate explanation is in @ref{Constructing a
tweak}:
-@lilypond[relative=1,verbatim]
+@lilypond[fragment,relative=1,verbatim]
c2\fermata
\override Script #'padding = #3
b2\fermata
@end itemize
-More specific overrides are also possible. The notation manual
-discusses in depth how to figure out these statements for yourself, in
-@ref{Tuning output}.
+More specific overrides are also possible. The next section
+discusses in depth how to figure out these statements for yourself.
+@node Constructing a tweak
+@subsection Constructing a tweak
+The general procedure of changing output, that is, entering
+a command like
-@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{\set} and @code{\unset}:
@example
- \set Context.propertyName = @var{value}
+ \override Voice.Stem #'thickness = #3.0
@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
+@noindent
+means that we have to determine these bits of information:
+@itemize
+@item the context: here @context{Voice}.
+@item the layout object: here @code{Stem}.
+@item the layout property: here @code{thickness}
+@item a sensible value: here @code{3.0}
+@end itemize
-@menu
-* Tuning objects::
-* Constructing a tweak::
-* Font selection::
-@end menu
+@cindex internal documentation
+@cindex finding graphical objects
+@cindex graphical object descriptions
+@cindex tweaking
+@cindex @code{\override}
+@cindex @code{\set}
+@cindex internal documentation
+We demonstrate how to glean this information from the notation manual
+and the program reference.
-@node Tuning objects
-@subsection Tuning objects
+@node Navigating the program reference
+@subsection Navigating the program reference
-@cindex object description
+Suppose we want to move the fingering indication in the fragment
+below:
-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}:
+@lilypond[fragment,relative=2,verbatim]
+c-2
+\stemUp
+f
+@end lilypond
-@example
- (thickness . 1.3)
- (beamed-lengths . (3.5 3.5 3.5 4.5 5.0))
- (Y-extent-callback . ,Stem::height)
- @var{...}
-@end example
+If you visit the documentation on fingering instructions (in
+@ref{Fingering instructions}), you will notice that there is written:
+@quotation
+@seealso
-Adding variables on top of this existing definition overrides the
-system default, and alters the resulting appearance of the layout
-object.
+Program reference: @internalsref{FingerEvent} and @internalsref{Fingering}.
-@syntax
+@end quotation
-Changing a variable for only one object is commonly achieved with
-@code{\once}:
-@example
-\once \override @var{context}.@var{objectname}
- @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.
+This fragment points to two parts of the program reference: a page
+on @code{FingerEvent} and on @code{Fingering}.
-In the following example, only one @internalsref{Stem} object is
-changed from its original setting:
+The page on @code{FingerEvent} describes the properties of the music
+expression for the input @code{-2}. The page contains many links
+forward. For example, it says
-@lilypond[verbatim,fragment,relative=1]
- c4
- \once \override Voice.Stem #'thickness = #4
- c4
- c4
-@end lilypond
-@cindex @code{\once}
-
-For changing more objects, the same command, without @code{\once} can
-be used:
-@example
-\override @var{context}.@var{objectname} @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
-
-Some examples:
-@lilypond[verbatim]
-c'4 \override Stem #'thickness = #4.0
-c'4
-c'4 \revert Stem #'thickness
-c'4
-@end lilypond
+@quotation
+ Accepted by: @internalsref{Fingering_engraver},
+@end quotation
-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]
- c'4 \override Stem #'thickness = #4.0
- c'4
- c'4 \override Stem #'thickness = #1.3
- c'4
-@end lilypond
+@noindent
+That link brings us to the documentation for the Engraver, the
+plug-in, which says
-Reverting a setting which was not set in the first place has no
-effect.
+@quotation
+ This engraver creates the following layout objects: @internalsref{Fingering}.
+@end quotation
+In other words, once the @code{FingerEvent}s are interpreted, the
+@code{Fingering_engraver} plug-in will process them.
+The @code{Fingering_engraver} is also listed to create
+@internalsref{Fingering} objects,
-@seealso
-Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
-@internalsref{PropertySet}, @internalsref{All-backend-properties}, and
-@internalsref{All-layout-objects}.
+ Lo and behold, that is also the
+second bit of information listed under @b{See also} in the Notation
+manual. By clicking around in the program reference, we can follow the
+flow of information within the program, either forward (like we did
+here), or backwards, following links like this:
+@itemize @bullet
-@refbugs
+@item @internalsref{Fingering}:
+ @internalsref{Fingering} objects are created by:
+ @b{@internalsref{Fingering_engraver}}
-The back-end is not very strict in type-checking object properties.
-Cyclic references in Scheme values for properties can cause hangs
-and/or crashes.
+@item @internalsref{Fingering_engraver}:
+Music types accepted: @b{@internalsref{fingering-event}}
+@item @internalsref{fingering-event}:
+Music event type @code{fingering-event} is in Music expressions named
+@b{@internalsref{FingerEvent}}
+@end itemize
-@menu
-* Constructing a tweak::
-* Applyoutput::
-* Font selection::
-* Text markup::
-@end menu
+This path goes against the flow of information in the program: it
+starts from the output, and ends at the input event.
-@node Constructing a tweak
-@subsection Constructing a tweak
+The program reference can also be browsed like a normal document. It
+contains a chapter on
+@ifhtml
+@internalsref{Music-definitions},
+@end ifhtml
+@ifnothtml
+@code{Music definitions}
+@end ifnothtml
+on @internalsref{Translation}, and the @internalsref{Backend}. Every
+chapter lists all the definitions used, and all properties that may be
+tuned.
+
+
+@node Layout interfaces
+@subsection Layout interfaces
+
+@cindex interface, layout
+@cindex layout interface
+
+The HTML page which we found in the previous section, describes the
+layout object called @internalsref{Fingering}. Such an object is a
+symbol within the score. It has properties, which store numbers (like
+thicknesses and directions), but also pointers to related objects. A
+layout object is also called @emph{grob},
+@cindex grob
+which is short for Graphical Object.
-@cindex internal documentation
-@cindex finding graphical objects
-@cindex graphical object descriptions
-@cindex tweaking
-@cindex @code{\override}
-@cindex @code{\set}
-@cindex internal documentation
+The page for @code{Fingering} lists the definitions for the
+@code{Fingering} object. For example, the page says
+@quotation
+ @code{padding} (dimension, in staff space):
+
+ @code{0.6}
+@end quotation
+which means that the number will be kept at a distance of at least 0.6
+of the note head.
-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'', select the correct version, and click then
-``Program reference.'' It is advisable to bookmark the local HTML
-files. 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: it is generated from the definitions that the
-program uses, and therefore it is strongly tied to the LilyPond
-version.
+Each layout object may have several functions as a notational or
+typographical element. For example, the Fingering object
+has the following aspects
+@itemize @bullet
+@item Its size is independent of the horizontal spacing, unlike slurs or beams.
-@c [TODO: revise for new site.]
+@item It is a piece of text. Granted, it is usually a very short text.
-Suppose we want to move the fingering indication in the fragment below:
+@item That piece of text is typeset with a font, unlike slurs or beams.
+@item Horizontally, the center of the symbol should be aligned to the
+center of the notehead
+@item Vertically, the symbol is placed next to the note and the staff.
-@lilypond[relative=2,verbatim]
-c-2
-\stemUp
-f
-@end lilypond
+@item The
+ vertical position is also coordinated with other super and subscript
+symbols.
+@end itemize
-If you visit the documentation of @code{Fingering} (in @ref{Fingering
-instructions}), you will notice that there is written:
+Each of these aspects is captured in a so-called @emph{interface},
+which are listed on the @internalsref{Fingering} page at the bottom
@quotation
-@seealso
+This object supports the following interfaces:
+@internalsref{item-interface},
+@internalsref{self-alignment-interface},
+@internalsref{side-position-interface}, @internalsref{text-interface},
+@internalsref{text-script-interface}, @internalsref{font-interface},
+@internalsref{finger-interface}, and @internalsref{grob-interface}.
+@end quotation
-Internals: @internalsref{FingerEvent} and @internalsref{Fingering}.
+Clicking any of the links will take you to the page of the respective
+object interface. Each interface has a number of properties. Some of
+them are not user-serviceable (``Internal properties''), but others
+are.
-@end quotation
+We have been talking of `the' @code{Fingering} object, but actually it
+does not amount to much. The initialization file
+@file{scm/define-grobs.scm} shows the soul of the `object',
-@separate
+@verbatim
+ (Fingering
+ . (
+ (print-function . ,Text_interface::print)
+ (padding . 0.6)
+ (staff-padding . 0.6)
+ (self-alignment-X . 0)
+ (self-alignment-Y . 0)
+ (script-priority . 100)
+ (font-encoding . number)
+ (font-size . -5)
+ (meta . ((interfaces . (finger-interface font-interface
+ text-script-interface text-interface
+ side-position-interface self-alignment-interface
+ item-interface))))
+ ))
+@end verbatim
@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}.
+As you can see, the @code{Fingering} object is nothing more than a
+bunch of variable settings, and the webpage in the Program Reference
+is directly generated from this definition.
-The Fingering object has a number of different functions, and each of
-those is captured in an interface. The interfaces are listed under
-@internalsref{Fingering} in the program reference.
+@node Determining the grob property
+@subsection Determining the grob property
+Recall that we wanted to change the position of the @b{2} in
+
+@lilypond[fragment,relative=2,verbatim]
+c-2
+\stemUp
+f
+@end lilypond
+
+Since the @b{2} is vertically positioned next to its note, we have to
+meddle with the interface associated with this positioning. This is
+done using @code{side-position-interface}. The page for this interface
+says
-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 property @code{direction} signifies where to put the
+ support). The property @code{direction} signifies where to put the
victim object relative to the support (left or right, up or down?)
@end quotation
@item padding
(dimension, in staff space)
- add this much extra space between objects that are next to each
-other. Default value: @code{0.6}
+ Add this much extra space between objects that are next to each
+ other.
@end table
@end quotation
fingering. The following command inserts 3 staff spaces of white
between the note and the fingering:
@example
-\once \override Fingering #'padding = #3
+\once \override Voice.Fingering #'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 \override Fingering
- #'padding = #3
+\once \override Voice.Fingering #'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
+
+In this case, the context for this tweak is @context{Voice}. This
+fact can also be deduced from the program reference, for the page for
+the @internalsref{Fingering_engraver} plug-in says
+
@quotation
-Fingering grobs are created by: @internalsref{Fingering_engraver} @c
+ Fingering_engraver is part of contexts: @dots{} @b{@internalsref{Voice}}
@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
- \override Fingering @dots{}
-@end example
+@node Difficult tweaks
+@subsection Difficult tweaks
-Of course, the tweak may also done in a larger context than
-@code{Voice}, for example, @internalsref{Staff} or
-@internalsref{Score}.
+There are two classes of difficult adjustments. First, when there are
+several of the same objects at one point, and you want to adjust only
+one. For example, if you want to change only one note head in a chord.
-@seealso
+In this case, the @code{\applyoutput} function must be used. The
+next example defines a Scheme function @code{set-position-font-size}
+that sets the @code{font-size} property, but only
+on objects that have @internalsref{note-head-interface} and are at the
+right Y-position.
+
+@lilypond[verbatim]
+#(define ((set-position-font-size pos size) grob origin current)
+ (let*
+ ((interfaces (ly:grob-property grob 'interfaces))
+ (position (ly:grob-property grob 'staff-position)))
+ (if (and
+
+ ; is this a note head?
+ (memq 'note-head-interface interfaces)
+
+ ; is the Y coordinate right?
+ (= pos position))
-Internals: the program reference 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.
+ ; then do it.
+ (set! (ly:grob-property grob 'font-size) size))))
+
+\relative {
+ c
+ \applyoutput #(set-position-font-size -2 4)
+ <c e g>
+}
+@end lilypond
+@noindent
+A similar technique can be used for accidentals. In that case, the
+function should check for @code{accidental-interface}.
+
+Another difficult adjustment is the appearance of spanner objects,
+such as slur and tie. Initially, only one of these objects is created,
+and they can be adjust with the normal mechanism. However, in some
+cases the spanners cross line breaks. If this happens, these objects
+are cloned. A separate object is created for every system that it is
+in. These are clones of the original object and inherit all
+properties, including @code{\override}s.
+
+In other words, an @code{\override} always affects all pieces of a
+broken spanner. To change only one part of a spanner at a line break,
+it is necessary to hook into the formatting process. The
+@code{after-line-breaking-callback} property contains the Scheme procedure
+that is called after line breaks have been determined, and layout
+objects have been split over different systems.
+
+In the following example, we define a procedure
+@code{my-callback}. This procedure
+
+@itemize @bullet
+@item
+determines if we have been split across line breaks
+@item
+if yes, retrieves all the split objects
+@item
+checks if we are the last of the split objects
+@item
+if yes, it sets @code{extra-offset}.
+@end itemize
+This procedure is installed into @internalsref{Tie}, so the last part
+of broken tie is translated up.
-@node Font selection
-@subsection Font selection
+@lilypond[verbatim,raggedright]
+#(define (my-callback grob)
+ (let* (
-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 a number:
-negative numbers make the font smaller, positive numbers larger. An
-example is given below:
-@c
-@lilypond[fragment,relative=1,verbatim]
- c4 c4 \set fontSize = #-1
- f4 g4
+ ; have we been split?
+ (orig (ly:grob-original grob))
+
+ ; if yes, get the split pieces (our siblings)
+ (siblings (if (ly:grob? orig) (ly:spanner-broken-into orig) '() )))
+
+
+ (if (and (>= (length siblings) 2)
+ (eq? (car (last-pair siblings)) grob))
+ (ly:grob-set-property! grob 'extra-offset '(-2 . 5))
+ )))
+
+\relative c'' {
+ \override Tie #'after-line-breaking-callback =
+ #my-callback
+ c1 ~ \break c2 ~ c
+}
@end lilypond
-This command will set @code{font-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 symbols for cue
-notes. An elaborate example of those is in
-@inputfileref{input/test,cue-notes.ly}.
-@cindex magnification
-@cindex cue notes
+When applying this trick, the new @code{after-line-breaking-callback}
+should also call the old @code{after-line-breaking-callback}, if there
+is one. For example, if using this with @code{Slur},
+@code{Slur::after_line_breaking} should also be called.
-The font used for printing a object can be selected by setting
-@code{font-name}, e.g.
-@example
- \override Staff.TimeSignature
- #'font-name = #"cmr17"
-@end example
+@node Fonts
+@section Fonts
-@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. The size of fonts selected in this way
-can be changed with the @code{font-magnification} property. For
-example, @code{2.0} blows up all letters by a factor 2 in both
-directions.
+@menu
+* Selecting font sizes::
+* Font selection::
+@end menu
-@cindex font size
-@cindex font magnification
-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}:
+@node Selecting font sizes
+@subsection Selecting font sizes
-@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}.
+The easiest method of setting the font size of any context, is by
+setting the @code{fontSize} property.
-@end table
+@lilypond[fragment,relative=1,verbatim]
+ c8
+ \set fontSize = #-4
+ c f
+ \set fontSize = #3
+ g
+@end lilypond
-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
- \override Lyrics .LyricText #'font-series = #'bold
- \override Lyrics .LyricText #'font-family = #'typewriter
- \override Lyrics .LyricText #'font-shape = #'*
-@end example
+It does not change the size of variable symbols, such as beams or
+slurs.
-@cindex @code{font-style}
+Internally, the @code{fontSize} context property will cause
+@code{font-size} property to be set in all layout objects. The value
+of @code{font-size} is a number indicating the size relative to the
+standard size for the current staff height. Each step up is an
+increase of approximately 12% of the font size. Six steps is exactly a
+factor two. The Scheme function @code{magstep} converts a
+@code{font-size} number to a scaling factor.
-The font size is set by modifying the @code{font-size} property. Its
-value is a number indicating the size relative to the standard size.
-Each step up is an increase of approximately 12% of the font size. Six
-steps is exactly a factor two. The Scheme function @code{magstep}
-converts a @code{font-size} number to a scaling factor.
+@lilypond[fragment,relative=1,verbatim]
+ c8
+ \override NoteHead #'font-size = #-4
+ c f
+ \override NoteHead #'font-size = #3
+ g
+@end lilypond
-LilyPond has fonts in different design sizes: the music fonts for
+LilyPond has fonts in different design sizes. The music fonts for
smaller sizes are chubbier, while the text fonts are relatively wider.
Font size changes are achieved by scaling the design size that is
-closest to the desired size.
+closest to the desired size. The standard font size (for
+@code{font-size} equals 0), depends on the standard staff height. For
+a 20 pt staff, a 10pt font is selected.
The @code{font-size} mechanism does not work for fonts selected
through @code{font-name}. These may be scaled with
-@code{font-magnification}.
+@code{font-magnification}. The @code{font-size} property can only be
+set on layout objects that use fonts; these are the ones supporting
+@internalsref{font-interface} layout interface.
@refcommands
-The following commands set @code{fontSize} for the current voice.
+The following commands set @code{fontSize} for the current voice:
@cindex @code{\tiny}
@code{\tiny},
@cindex @code{\normalsize}
@code{\normalsize}.
-@seealso
-Init files: @file{ly/declarations-init.ly} contains hints how new
-fonts may be added to LilyPond.
-@refbugs
+@cindex magnification
+@cindex cue notes
+
+
+@node Font selection
+@subsection Font selection
+
-There is no style sheet provided for other fonts besides the @TeX{}
-Computer Modern family.
@cindex font selection
@cindex font magnification
@cindex @code{font-interface}
+By setting the object properties described below, you can select a
+font from the preconfigured font families. LilyPond has default
+support for the feta music fonts and @TeX{}'s Computer Modern text
+fonts.
+
+
+@itemize @bullet
+@item @code{font-encoding}
+is a symbol that sets layout of the glyphs. Choices include @code{ec}
+for @TeX{} EC font encoding, @code{fetaBraces} (for piano staff
+braces), @code{fetaMusic} (the standard music font, including ancient
+glyphs), @code{fetaDynamic} (for dynamic signs) and @code{fetaNumber}
+for the number font.
+
+
+@item @code{font-family}
+ is a symbol indicating the general class of the typeface. Supported are
+@code{roman} (Computer Modern), @code{sans}, and @code{typewriter}.
+
+@item @code{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 @code{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}.
+
+@end itemize
+
+Fonts selected in the way sketched above come from a predefined style
+sheet.
+
+ The font used for printing a object can be selected by setting
+@code{font-name}, e.g.
+@example
+ \override Staff.TimeSignature
+ #'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. The size of fonts selected in this way
+can be changed with the @code{font-magnification} property. For
+example, @code{2.0} blows up all letters by a factor 2 in both
+directions.
+
+@cindex font size
+@cindex font magnification
+
+
+
+@seealso
+
+Init files: @file{ly/declarations-init.ly} contains hints how new
+fonts may be added to LilyPond.
+
+
@node Text markup
@section Text markup
@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:
+The internal mechanism to typeset texts is accessed with the keyword
+@code{\markup}. Within markup mode, you can enter texts similar to
+lyrics. They are simply entered, while commands use the backslash @code{\}.
@cindex markup
@lilypond[verbatim,fragment,relative=1]
@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
+command @code{\bold} and @code{\italic} apply to the first following
+word only; enclose a set of texts with braces to apply a command
to more words:
@example
\markup @{ \bold @{ hi there @} @}
In markup mode you can compose expressions, similar to mathematical
-expressions, XML documents and music expressions. The braces group
+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
+stack expressions grouped with @code{<} and @code{>} vertically with
the command @code{\column}. Similarly, @code{\center-align} aligns
texts by their center lines:
may be attached to notes, like
@verbatim
allegro = \markup { \bold \large { Allegro } }
-\notes { a^\allegro b c d }
+ { a^\allegro b c d }
@end verbatim
any effects of alignments applied to their markup arguments as a
whole. For example, the @internalsref{RehearsalMark} is horizontally
centered, so using @code{\mark \markup @{ \left-align .. @}} has no
-effect. Similarly, whole texts over notes cannot be moved vertically
-with @code{\raise}. For moving and aligning complete objects, grob
-properties should be used.
+effect.
+
+Similarly, for moving whole texts over notes with
+@code{\raise}, use the following trick:
+@lilypond[verbatim]
+{
+ c'^\markup { \raise #0.5 not-raised }
+ c'^\markup { "" \raise #0.5 raised }
+}
+@end lilypond
+
+On the second note, the text @code{raised} is moved relative to the
+empty string @code{""} which is not visible. Alternatively, complete
+objects can be moved with layout properties such as @code{padding} and
+@code{extra-offset}.
+
@refbugs
-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.
+No kerning or generation of ligatures is only done when the by @TeX{}
+backend is used. In this case, LilyPond does not account for them 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.
-
-
@menu
+* Text encoding::
+* Nested scores::
* Overview of text markup commands::
@end menu
+@node Text encoding
+@subsection Text encoding
+
+Texts can be entered in different encodings. The encoding of the
+file can be set with @code{\encoding}.
+
+@example
+ \encoding "latin1"
+@end example
+
+This command may be placed anywhere in the input file. The current
+encoding is passed as an extra argument to @code{\markup} commands,
+and is passed similarly to lyric syllables.
+
+If no @code{\encoding} has been specified, then the encoding is taken
+from the @code{\layout} block (or @code{\paper}, if @code{\layout}
+does not specify encoding). The variable @code{inputencoding} may be
+set to a string or symbol specifying the encoding, e.g.
+
+@verbatim
+ \layout {
+ inputencoding = "latin1"
+ }
+@end verbatim
+
+Normal strings, are unaffected by @code{\encoding}. This means that
+the following will usually not produce ba@ss{}tuba in the title.
+
+@verbatim
+ \header {
+ title = "Grazing cow"
+ instrument = "Baßtuba"
+ }
+@end verbatim
+
+Rather, you should say
+@verbatim
+ instrument = \markup { Baßtuba }
+@end verbatim
+
+@noindent
+or set @code{inputencoding} in the @code{\paper} block.
+
+There is a special encoding, called @code{TeX}. This encoding does not
+reencode text for the font used. Rather, it tries to guess the width
+of @TeX{} commands, such as @code{\"}. Strings encoded with @code{TeX}
+are passed to the output back-end verbatim.
+
+@cindex encoding
+@cindex @code{\encoding}
+@cindex inputencoding
+@cindex @TeX{} commands in strings
+
+
+@node Nested scores
+@subsection Nested scores
+
+It is possible to nest music inside markups, by adding a @code{\score}
+block to markup expression. Such a score must contain a @code{\layout}
+block.
+
+@lilypond[verbatim,raggedright]
+\relative {
+ c4 d^\markup {
+ \score {
+ \relative { c4 d e f }
+ \layout { }
+ }
+ }
+ e f
+}
+@end lilypond
+
+
+
@node Overview of text markup commands
@subsection Overview of text markup commands
+The following commands can all be used inside @code{\markup @{ @}}.
+
@include markup-commands.tely
@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
+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. This section
-explains how to tune the algorithm for spacing.
+which influences where line breaks are chosen, and thus ultimately how
+many pages a piece of music takes.
+
+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.
+
+After spacing and linebreaking, the systems are distributed across
+pages, taking into account the size of the page, and the size of the
+titles.
+
+
+
+@menu
+* Setting global staff size::
+* Vertical spacing of piano staves::
+* Vertical spacing::
+* Horizontal spacing::
+* Line length::
+* Line breaking::
+* Multiple movements::
+* Creating titles::
+* Page breaking::
+* paper size::
+* Page layout::
+@end menu
+
+
+@node Setting global staff size
+@subsection Setting global staff size
+
+@cindex font size, setting
+@cindex staff size, setting
+@cindex @code{layout} file
+
+The Feta font provides musical symbols at eight different
+sizes. Each font is tuned for a different staff size: at a smaller size
+the font becomes heavier, to match the relatively heavier staff lines.
+The recommended font sizes are listed in the following table:
+
+@multitable @columnfractions .25 .25 .25 .25
+
+@item @b{font name}
+@tab @b{staff height (pt)}
+@tab @b{staff height (mm)}
+@tab @b{use}
+
+@item feta11
+@tab 11.22
+@tab 3.9
+@tab pocket scores
+
+@item feta13
+@tab 12.60
+@tab 4.4
+@tab
+
+@item feta14
+@tab 14.14
+@tab 5.0
+@tab
+
+@item feta16
+@tab 15.87
+@tab 5.6
+@tab
+
+@item feta18
+@tab 17.82
+@tab 6.3
+@tab song books
+
+@item feta20
+@tab 20
+@tab 7.0
+@tab standard parts
+
+@item feta23
+@tab 22.45
+@tab 7.9
+@tab
+
+@item feta26
+@tab 25.2
+@tab 8.9
+@tab
+@c modern rental material ?
+
+@end multitable
+
+These fonts are available in any sizes. The context property
+@code{fontSize} and the layout property @code{staff-space} (in
+@internalsref{StaffSymbol}) can be used to tune size for individual
+staves. The size of individual staves are relative to the global size,
+which can be set in the following manner:
+
+@example
+ #(set-global-staff-size 14)
+@end example
+
+This sets the global default size to 14pt staff height, and scales all
+fonts accordingly.
+
+@seealso
+
+This manual: @ref{Selecting font sizes}.
+
+
+
+
+@node Vertical spacing of piano staves
+@subsection Vertical spacing of piano staves
+
+The distance between staves of a @internalsref{PianoStaff} cannot be
+computed during formatting. Rather, to make cross-staff beaming work
+correctly, that distance has to be fixed beforehand.
+
+The distance of staves in a @code{PianoStaff} is set with the
+@code{forced-distance} property of the
+@internalsref{VerticalAlignment} object, created in
+@internalsref{PianoStaff}.
+
+It can be adjusted as follows
+@verbatim
+\new PianoStaff \with {
+ \override VerticalAlignment #'forced-distance = #7
+} {
+ ...
+}
+@end verbatim
+This would bring the staves together at a distance of 7 staff spaces,
+measured from the center line of each staff.
-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.
+The difference is demonstrated in the following example,
+@lilypond[verbatim]
+\relative <<
+ \new PianoStaff \with {
+ \override VerticalAlignment #'forced-distance = #7
+ } <<
+ \new Staff { c1 }
+ \new Staff { c }
+ >>
+ \new PianoStaff <<
+ \new Staff { c }
+ \new Staff { c }
+ >>
+>>
+@end lilypond
-@menu
-* Vertical spacing::
-* Horizontal spacing::
-* Font Size::
-* Line breaking::
-* Page layout::
-@end menu
+@refbugs
+@code{forced-distance} cannot be changed per system.
@node Vertical spacing
@subsection Vertical spacing
@cindex distance between staves
@cindex staff distance
@cindex between staves, distance
-@cindex staffs per page
+@cindex staves 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.
+The height of each system is determined automatically. To prevent
+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
+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 default, then you could set
@example
\set Staff.minimumVerticalExtent = #'(-4 . 4)
@end example
@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)}.
+. 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
- \paper @{
- \translator @{
- \PianoStaffContext
- \override VerticalAlignment #'forced-distance = #9
- @}
- @dots{}
- @}
-@end example
-This would bring the staves together at a distance of 9 staff spaces,
-measured from the center line of each staff.
@seealso
Internals: Vertical alignment of staves is handled by the
@internalsref{VerticalAlignment} object.
+@refbugs
+
+@code{minimumVerticalExtent} is syntactic sugar for setting
+@code{minimum-Y-extent} of the @internalsref{VerticalAxisGroup} of the
+current context. It can only be changed score wide.
@subsection Horizontal Spacing
The spacing engine translates differences in durations into
-stretchable distances (``springs'') of differing lengths. Longer
+stretchable distances (``springs'') of differring 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).
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
+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
+@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 (i.e. 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.
+Normally, @code{spacing-increment} is set to 1.2 staff space, which is
+approximately the width of a note head, and
+@code{shortest-duration-space} is set to 2.0, meaning that the
+shortest note gets 2.4 staff space (2.0 times the
+@code{spacing-increment}) of horizontal space. This space is 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 1 NHW 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 proportional 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:
+thus adding 1 NHW to every note. To prevent this, the shortest
+duration for spacing is not the shortest note in the score, but rather
+the one which occurs most frequently.
-@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}.
+1/8th note. The shortest duration is printed when you run
+@code{lilypond} with the @code{--verbose} option.
+
+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
+Notes that are even shorter than the commoon shortest note are
+followed by a space that is proportional 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
+
+
+In the introduction (see @ref{Engraving}), it was explained that stem
+directions influence spacing. This is controlled with the
+@code{stem-spacing-correction} property in the
+@internalsref{NoteSpacing}, object. These are generated for every
@internalsref{Voice} context. The @code{StaffSpacing} object
(generated at @internalsref{Staff} context) contains the same property
-for controlling the stem/bar line spacing. The following example
-shows these corrections, once with default settings, and once with
+for controlling the stem/bar line spacing. The following example shows
+these corrections, once with default settings, and once with
exaggerated corrections:
-@lilypond
- \score { \notes {
+@lilypond[raggedright]
+{
c'4 e''4 e'4 b'4 |
b'4 e''4 b'4 e''4|
- \override Staff.NoteSpacing #'stem-spacing-correction
- = #1.5
- \override Staff.StaffSpacing #'stem-spacing-correction
- = #1.5
+ \override Staff.NoteSpacing #'stem-spacing-correction = #1.5
+ \override Staff.StaffSpacing #'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 property commands are interpreted.
-@example
-\paper @{ \translator @{
- \ScoreContext
- SpacingSpanner \override #'spacing-increment = #3.0
-@} @}
-@end example
-
@seealso
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 eight seven different
-sizes. Each font is tuned for a different staff size: at smaller sizes
-the font gets heavier, to match the relatively heavier staff lines.
-The recommended font sizes are listed in the following table:
-
-@multitable @columnfractions .25 .25 .25 .25
-
-@item @b{name}
-@tab @b{staff height (pt)}
-@tab @b{staff height (mm)}
-@tab @b{use}
-
-@item feta11
-@tab 11.22
-@tab 3.9
-@tab pocket scores
-
-@item feta13
-@tab 12.60pt
-@tab 4.4mm
-@tab
-
-@item feta14
-@tab 14.14pt
-@tab 5.0mm
-@tab
-
-@item feta16
-@tab 15.87pt
-@tab 5.6mm
-@tab
-
-@item feta18
-@tab 17.82pt
-@tab 6.3mm
-@tab song books
+There is no convenient mechanism to manually override spacing. The
+following work-around may be used to insert extra space into a score.
+@example
+ \once \override Score.SeparationItem #'padding = #1
+@end example
-@item feta20
-@tab 17.82pt
-@tab 7.0mm
-@tab standard parts
+No work-around exists for decreasing the amount of space.
-@item feta23
-@tab 22.45 pt
-@tab 7.9mm
-@tab
+@node Line length
+@subsection Line length
-@item feta20
-@tab 25.2 pt
-@tab 8.9mm
-@tab
-@c modern rental material ?
+@cindex page breaks
+@cindex breaking pages
-@end multitable
+@cindex @code{indent}
+@cindex @code{linewidth}
-These fonts are available in any sizes. The context property
-@code{fontSize} and the layout property @code{staff-space} (in
-@internalsref{StaffSymbol}) can be used to tune size for individual
-staffs. The size of individual staffs are relative to the global size,
-which can be set in the following manner:
+@c Although linewidth can be set in \layout, it should be set in paper
+@c block, to get page layout right.
+@c Setting indent in \paper block makes not much sense, but it works.
-@example
- #(set-global-staff-size 14)
-@end example
+@c Bit verbose and vague, use examples?
+The most basic settings influencing the spacing are @code{indent} and
+@code{linewidth}. They are set in the @code{\layout} block. They
+control the indentation of the first line of music, and the lengths of
+the lines.
-This sets the global default size to 14pt staff height, and scales all
-fonts accordingly.
+If @code{raggedright} is set to true in the @code{\layout} 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 option @code{raggedlast} is similar to @code{raggedright}, but
+only affects the last line of the piece. No restrictions are put on
+that line. The result is similar to formatting text paragraphs. In a
+paragraph, the last line simply takes its natural length.
+@c Note that for text there are several options for the last line.
+@c While Knuth TeX uses natural length, lead typesetters use the same
+@c stretch as the previous line. eTeX uses \lastlinefit to
+@c interpolate between both these solutions.
@node Line breaking
@subsection Line breaking
@refcommands
-@code{\break}, @code{\noBreak}
+@code{\break}, and @code{\noBreak}.
@cindex @code{\break}
@cindex @code{\noBreak}
Internals: @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.
+@node Multiple movements
+@subsection Multiple movements
-@cindex page layout
-@cindex vertical spacing
+@cindex bibliographic information
+@cindex titles
+@cindex composer
+@cindex Engraved by LilyPond
-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{lilypond} wrapper program. It
-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}
+A document may contains multiple pieces of music. Examples of these
+are an etude book, or an orchestral part with multiple movements.
+Each movement is entered with a @code{\score} block,
-To change the paper size, use the following Scheme code:
@example
- \paper@{
- #(set-paper-size "a4")
- @}
+ \score @{
+ @var{..music..}
+ @}
@end example
+The movements are combined together to
+@code{\book} block is used to group the individual movements.
-@refcommands
-
-@cindex @code{\newpage}
-@code{\newpage}.
-
-
-@seealso
-
-In this manual: @ref{Invoking lilypond}.
-
-Examples: @inputfileref{input/regression,between-systems.ly}.
-
-Internals: @internalsref{NonMusicalPaperColumn}.
-
-@refbugs
-
-LilyPond has no concept of page layout, which makes it difficult to
-reliably choose page breaks in longer pieces.
-
-
-@node Interpretation context
-@section Interpretation context
-
-@menu
-* Creating contexts::
-* Default contexts::
-* Context properties::
-* Defining contexts::
-* Changing contexts locally::
-* Engravers and performers::
-* Defining new contexts::
-@end menu
-
-
-Interpretation contexts are objects that only exist during program
-run. During the interpretation phase (when @code{interpreting music}
-is printed on the standard output), the music expression in a
-@code{\score} block is interpreted in time order, the same order in
-which we hear and play the music. During this phase, the interpretation
-context holds the state for the current point within the music, for
-example:
-@itemize @bullet
-@item What notes are playing at this point?
+@example
+\book @{
+ \score @{
+ @var{..}
+ @}
+ \score @{
+ @var{..}
+ @}
+@}
+@end example
-@item What symbols will be printed at this point?
-@item What is the current key signature, time signature, point within
-the measure, etc.?
-@end itemize
+The header for each piece of music can be put inside the @code{\score}
+block. The @code{piece} name from the header will be printed before
+each movement. The title for the entire book can be put inside the
+@code{\book}, but if it is not present, the @code{\header} which is at
+the top of the file is inserted.
-Contexts are grouped hierarchically: A @internalsref{Voice} context is
-contained in a @internalsref{Staff} context (because a staff can contain
-multiple voices at any point), a @internalsref{Staff} context is contained in
-@internalsref{Score}, @internalsref{StaffGroup}, or
-@internalsref{ChoirStaff} context.
+@cindex Engraved by LilyPond
+@cindex signature line
-Contexts associated with sheet music output are called @emph{notation
-contexts}, those for sound output are called @emph{performance
-contexts}. The default definitions of the standard notation and
-performance contexts can be found in @file{ly/engraver-init.ly} and
-@file{ly/performer-init.ly}, respectively.
+@example
+\book @{
+ \header @{
+ title = "Eight miniatures"
+ composer = "Igor Stravinsky"
+ @}
+ \score @{
+ @dots{}
+ \header @{ piece = "Romanze" @}
+ @}
+ \score @{
+ @dots{}
+ \header @{ piece = "Menuetto" @}
+ @}
+@}
+@end example
+@node Creating titles
+@subsection Creating titles
-@node Creating contexts
-@subsection Creating contexts
-@cindex @code{\context}
-@cindex context selection
+Titles are created for each @code{\score} block, and over a
+@code{\book}.
-Contexts for a music expression can be selected manually, using one of
-the following music expressions:
+The contents of the titles are taken from the @code{\header} blocks.
+The header block for a book supports the following
+@table @code
+@item title
+ The title of the music. Centered on top of the first page.
+@item subtitle
+ Subtitle, centered below the title.
+@item poet
+ Name of the poet, left flushed below the subtitle.
+@item composer
+ Name of the composer, right flushed below the subtitle.
+@item meter
+ Meter string, left flushed below the poet.
+@item opus
+ Name of the opus, right flushed below the composer.
+@item arranger
+ Name of the arranger, right flushed below the opus.
+@item instrument
+ Name of the instrument, centered below the arranger.
+@item dedication
+ To whom the piece is dedicated.
+@item piece
+ Name of the piece, left flushed below the instrument.
+@end table
-@example
-\new @var{contexttype} @var{musicexpr}
-\context @var{contexttype} [= @var{contextname}] @var{musicexpr}
-@end example
+This is a demonstration of the fields available,
-@noindent
-This means that @var{musicexpr} should be interpreted within a context
-of type @var{contexttype} (with name @var{contextname} if specified).
-If no such context exists, it will be created:
+@lilypond[verbatim]
+\book {
+ \header {
+ title = "Title"
+ subtitle = "and the subtitle"
+ subsubtitle = "Sub sub title"
+ poet = "Poet"
+ composer = "Composer"
+ texttranslator = "Text Translator"
+ meter = "Meter"
+ arranger = "Arranger"
+ instrument = "Instrument"
+ piece = "Piece"
+ }
-@lilypond[verbatim,raggedright]
-\score {
- \notes \relative c'' {
- c4 <<d4 \context Staff = "another" e4>> f
+ \score {
+ \header {
+ piece = "piece1"
+ opus = "opus1"
+ }
+ { c'1 }
+ }
+ \score {
+ \header {
+ piece = "piece2"
+ opus = "opus2"
+ }
+ { c'1 }
+ }
+ \paper {
+ linewidth = 8.0 \cm
}
}
@end lilypond
-@noindent
-In this example, the @code{c} and @code{d} are printed on the default
-staff. For the @code{e}, a context @code{Staff} called @code{another}
-is specified; since that does not exist, a new context is created.
-Within @code{another}, a (default) Voice context is created for the
-@code{e4}. A context is ended when when all music referring it has
-finished, so after the third quarter, @code{another} is removed.
+Different fonts may be selected for each element, by using a
+@code{\markup}, e.g.
-The @code{\new} construction creates a context with a
-generated, unique @var{contextname}. An expression with
-@code{\new} always leads to a new context. This is convenient
-for creating multiple staffs, multiple lyric lines, etc.
+@verbatim
+ \header {
+ title = \markup { \italic { The italic title } }
+ }
+@end verbatim
-When using automatic staff changes, automatic phrasing, etc., the
-context names have special meanings, so @code{\new} cannot be
-used.
+A more advanced option is to change the Scheme functions
+@code{make-book-title} and @code{make-score-title} functions, defined
+in the @code{\paper} of the @code{\book} block. These functions
+create a block of titling, given the information in the
+@code{\header}. The init file @file{ly/titling.scm} shows how the
+default format is created, and it may be used as a template for
+different styles.
+
+
+@cindex \paper
+@cindex header
+@cindex footer
+@cindex page layout
+@cindex titles
-@node Default contexts
-@subsection Default contexts
-Every top level music is interpreted by the @code{Score} context; in
-other words, you may think of @code{\score} working like
-@example
-\score @{
- \context Score @var{music}
-@}
-@end example
+@node Page breaking
+@subsection Page breaking
-Music expressions inherit their context from the enclosing music
-expression. Hence, it is not necessary to explicitly specify
-@code{\context} for most expressions. In
-the following example, only the sequential expression has an explicit
-context. The notes contained therein inherit the @code{goUp} context
-from the enclosing music expression.
+The default page breaking may be overriden by inserting
+@code{\pageBreak} or @code{\noPageBreak} commands. These commands are
+analogous to @code{\break} and @code{\noBreak}. They should be
+inserted with a bar line. These commands force and forbid a page-break
+from happening. Of course, the @code{\pageBreak} command also forces
+a line break.
-@lilypond[verbatim,raggedright]
- \notes \context Voice = goUp { c'4 d' e' }
-@end lilypond
+Page breaks are computed by the @code{page-breaking} function in the
+@code{\paper} block.
+@refcommands
-Second, contexts are created automatically to be able to interpret the
-music expressions. Consider the following example:
+@cindex @code{\pageBreak}
+@code{\pageBreak}
+@cindex @code{\noPageBreak}
+@code{\noPageBreak}
-@lilypond[verbatim,raggedright]
- \score { \notes { c'4-( d' e'-) } }
-@end lilypond
+@node paper size
+@subsection paper size
-@noindent
-The sequential music is interpreted by the Score context initially,
-but when a note is encountered, contexts are setup to accept that
-note. In this case, a @code{Voice}, and @code{Staff}
-context are created. The rest of the sequential music is also
-interpreted with the same @code{Voice}, and
-@code{Staff} context, putting the notes on the same staff, in the same
-voice.
-
-@node Context properties
-@subsection Context properties
-
-Contexts have properties. These properties are set from the @file{.ly}
-file using the following expression:
-@cindex context properties
-@cindex properties, context
+@cindex paper size
+@cindex page size
+@cindex @code{papersize}
+To change the paper size, there are two commands,
@example
-\set @var{contextname}.@var{propname} = @var{value}
+ #(set-default-paper-size "a4")
+ \layout@{
+ #(set-paper-size "a4")
+ @}
@end example
+The second one sets the size of the @code{\layout} block that it is in.
-@noindent
-Sets the @var{propname} property of the context @var{contextname} to
-the specified Scheme expression @var{value}. Both @var{propname} and
-@var{contextname} are strings, which can often be written unquoted.
+The following paper sizes are supported.
-@cindex inheriting
-Properties that are set in one context are inherited by all of the
-contained contexts. This means that a property valid for the
-@internalsref{Voice} context can be set in the @internalsref{Score} context
-(for example) and thus take effect in all @internalsref{Voice} contexts.
+@table @code
+@item a6
+@item a5
+@item a4
+@item a3
+@item legal
+@item letter
+@item tabloid
+@end table
+
+@cindex orientation
+@cindex landscape
+
+If the symbol @code{landscape} is supplied as argument to
+@code{set-default-paper-size}, the pages will be rotated 90 degrees,
+and line widths will be set longer correspondingly.
-Properties can be unset using the following statement.
@example
-\unset @var{contextname}.@var{propname}
-@end example
+#(set-default-paper-size "a6" 'landscape)
+@end example
-@cindex properties, unsetting
-@cindex @code{\unset}
+@node Page layout
+@subsection Page layout
-@noindent
-This removes the definition of @var{propname} in @var{contextname}. If
-@var{propname} was not defined in @var{contextname} (but was inherited
-from a higher context), then this has no effect.
+@cindex page layout
+@cindex margins
+@cindex header, page
+@cindex footer, page
-If @var{contextname} is left out, then it defaults to the current
-``bottom'' context: this is a context like @internalsref{Voice} that
-cannot contain any other contexts.
+LilyPond will do page layout, setting margins and adding headers and
+footers to each page.
+The default layout responds to the following settings in the
+@code{\paper} block
-@node Defining contexts
-@subsection Defining contexts
+@cindex \paper
-@cindex context definition
-@cindex translator definition
+@table @code
+@item firstpagenumber
+ The value of the page number of the first page. Default is 1.
+@item printfirstpagenumber
+ If set to true will print the page number in the first page. Default is
+ false.
+@item hsize
+ The width of the page
+@item vsize
+ The height of the page
+@item topmargin
+ Margin between header and top of the page
+@item bottommargin
+ Margin between footer and bottom of the page
+@item leftmargin
+ Margin between the left side of the page and the beginning of the music
+@item linewidth
+ The length of the systems
+@item headsep
+ Distance between top-most music system and the page header
+@item footsep
+ Distance between bottom-most music system and the page footer
+@item raggedbottom
+ If set to true, systems will not be spread across the page.
+
+ This should be set false for pieces that have only two or three
+systems per page, for example orchestral scores.
+
+@item raggedlastbottom
+ If set to false, systems will be spread to fill the last page.
+
+ Pieces that amply fill two pages or more should have this set to
+true.
+
+@item betweensystemspace
+ This dimensions determines the distance between systems. It is the
+ideal distance between the center of the bottom staff of one system,
+and the center of the top staff of the next system.
+
+Increasing this will provide a more even appearance of the page at the
+cost of using more vertical space.
+
+@item betweensystempadding
+This dimension is the minimum amount of white space that will always
+be present between the bottom most symbol of one system, and the
+topmost of the next system.
+
+Increasing this will put systems whose bounding boxes almost touch
+farther apart.
+
+@item aftertitlespace
+Amount of space between title and the first system
+@item beforetitlespace
+Amount of space between last system of the previous piece and the
+title of the next
+@item betweentitlespace
+Amount of space between consecutive titles (eg. the title of the
+book and the title of piece).
-The most common way to create a new context definition is by extending
-an existing one. An existing context from the paper block is copied
-by referencing a context identifier:
+@end table
@example
-\paper @{
- \translator @{
- @var{context-identifier}
- @}
-@}
+ \paper@{
+ hsize = 2\cm
+ topmargin = 3\cm
+ bottommargin = 3\cm
+ raggedlastbottom = ##t
+ @}
@end example
-@noindent
-Every predefined context has a standard identifier. For example, the
-@code{Staff} context can be referred to as @code{\StaffContext}.
+You can also define these values in scheme. In that case @code{mm},
+@code{in}, @code{pt} and @code{cm} are variables defined in
+@file{paper-defaults.ly} with values in millimeters. That's why the
+value has to be multiplied in the example above.
-The context can then be modified by setting or changing properties,
-e.g.
@example
-\translator @{
- \StaffContext
- Stem \set #'thickness = #2.0
- defaultBarType = #"||"
-@}
+ \paper@{
+ #(define bottommargin (* 2 cm))
+ @}
@end example
-These assignments happen before interpretation starts, so a property
-command will override any predefined settings.
-@cindex engraver
+@cindex copyright
+@cindex tagline
-@refbugs
-
-It is not possible to collect multiple property assignments in a
-variable, and apply to one @code{\translator} definition by
-referencing that variable.
+The default footer is empty, except for the first page, where it the
+@code{copyright} field from @code{\header} is inserted, and the last
+page, where @code{tagline} from @code{\header} is added. The default
+tagline is ``Engraved by LilyPond (@var{version})''.@footnote{Nicely
+printed parts are good PR for us, so please leave the tagline if you
+can.}
-@node Changing contexts locally
-@subsection Changing contexts locally
+The header and footer are created by the functions @code{make-footer}
+and @code{make-header}, defined in @code{\paper}. The default
+implementations are in @file{scm/page-layout.scm}.
+The following settings influence the header and footer layout.
-Extending an existing context can also be done locally. A piece of
-music can be interpreted in a changed context by using the following syntax
+@table @code
+@item printpagenumber
+ this boolean controls whether a pagenumber is printed.
+@end table
-@example
- \with @{
- @var{context modifications}
- @}
-@end example
+The page layout itself is done by two functions in the
+@code{\paper}, @code{page-music-height} and
+@code{page-make-stencil}. The former tells the line-breaking algorithm
+how much space can be spent on a page, the latter creates the actual
+page given the system to put on it.
-These statements comes between @code{\new} or @code{\context} and the
-music to be interpreted. The @var{context modifications} property
-settings and @code{\remove}, @code{\consists} and @code{\consistsend}
-commands. The syntax is similar to the @code{\translator} block.
-The following example shows how a staff is created with bigger spaces,
-and without a @code{Clef_engraver}.
+@seealso
-@lilypond[relative=1,fragment,verbatim]
-<<
- \new Staff { c4 es4 g2 }
- \new Staff \with {
- \override StaffSymbol #'staff-space = #(magstep 1.5)
- fontSize = #1.5
- \remove "Clef_engraver"
- } {
- c4 es4 g2
- } >>
-@end lilypond
+Examples: @inputfileref{input/test,page-breaks.ly}
@refbugs
-The command @code{\with} has no effect on contexts that already
-exist.
+The option rightmargin is defined but doesn't set the right margin
+yet. The value for the right margin has to be defined adjusting the
+values of the leftmargin and linewidth.
+The default page header puts the page number and the @code{instrument}
+field from the @code{\header} block on a line.
-@node Engravers and performers
-@subsection Engravers and performers
-Each context is composed of a number of building blocks, or plug-ins
-called engravers. An engraver is a specialized C++ class that is
-compiled into the executable. Typically, an engraver is responsible
-for one function: the @code{Slur_engraver} creates only @code{Slur}
-objects, and the @code{Skip_event_swallow_translator} only swallows
-(silently gobbles) @code{SkipEvent}s.
+@node File structure
+@section File structure
-
-
-@cindex engraver
-@cindex plug-in
-
-An existing context definition can be changed by adding or removing an
-engraver. The syntax for these operations is
+The bigger part of this manual is concerned with entering various
+forms of music in LilyPond. However, many music expressions are not
+valid input on their own, for example, a @code{.ly} file containing
+only a note
@example
-\consists @var{engravername}
-\remove @var{engravername}
+ c'4
@end example
-@cindex @code{\consists}
-@cindex @code{\remove}
-
@noindent
-Here @var{engravername} is a string, the name of an engraver in the
-system. In the following example, the @code{Clef_engraver} is removed
-from the Staff context. The result is a staff without a clef, where
-the middle C is at its default position, the center line:
-
-@lilypond[verbatim,raggedright]
-\score {
- \notes {
- c'4 f'4
- }
- \paper {
- \translator {
- \StaffContext
- \remove Clef_engraver
- }
- }
-}
-@end lilypond
-
-A list of all engravers is in the internal documentation,
-see @internalsref{Engravers}.
-
-@node Defining new contexts
-@subsection Defining new contexts
-
+will result in a parsing error. Instead, music should be inside other
+expressions, which may be put in a file by themselves. Such
+expressions are called toplevel expressions. This section enumerates
+them all.
-It is also possible to define new contexts from scratch. To do this,
-you must define give the new context a name. In the following
-example, a very simple Staff context is created: one that will put
-note heads on a staff symbol.
-
-@example
-\translator @{
- \type "Engraver_group_engraver"
- \name "SimpleStaff"
- \alias "Staff"
- \consists "Staff_symbol_engraver"
- \consists "Note_head_engraver"
- \consistsend "Axis_group_engraver"
-@}
-@end example
+A @code{.ly} file contains any number of toplevel expressions, where a
+toplevel expressions is one of the following
-@noindent
-The argument of @code{\type} is the name for a special engraver that
-handles cooperation between simple engravers such as
-@code{Note_head_engraver} and @code{Staff_symbol_engraver}. This
-should always be @code{Engraver_group_engraver} (unless you are
-defining a Score context from scratch, in which case
-@code{Score_engraver} must be used).
-
-The complete list of context modifiers is the following:
@itemize @bullet
-@item @code{\alias} @var{alternate-name}:
-This specifies a different name. In the above example,
-@code{\set Staff.X = Y} will also work on @code{SimpleStaff}s.
-
-@item @code{\consistsend} @var{engravername}:
-Analogous to @code{\consists}, but makes sure that
-@var{engravername} is always added to the end of the list of
-engravers.
-
-Engravers that group context objects into axis groups or alignments
-need to be at the end of the list. @code{\consistsend} insures that
-engravers stay at the end even if a user adds or removes engravers.
-
-@item @code{\accepts} @var{contextname}:
-This context can contains @var{contextname} contexts. The first
-@code{\accepts} is created as a default context when events (e.g. notes
-or rests) are encountered.
-
-@item @code{\denies}:
-The opposite of @code{\accepts}.
-
-@item @code{\name} @var{contextname}:
-This sets the type name of the context, e.g. @code{Staff},
-@code{Voice}. If the name is not specified, the translator will not
-do anything.
-@end itemize
+@item An output definition, such as @code{\paper}, @code{\midi}
+and @code{\layout}. Such a definition at toplevel changes the default
+settings for the block entered.
-@c EOF
+@item An @code{\header} block. This sets the global header block. This
+is the block containing the definitions for book-wide settings, like
+composer, title, etc.
+@item An @code{\addquote} statement. See @ref{Quoting other voices}
+for more information.
+@item A @code{\score} block. This score will be collected with other
+toplevel scores, and combined as a single @code{\book}.
+This behavior can be changed by setting the variable
+@code{toplevel-score-handler} at toplevel. The default handler is
+defined in the init file @file{scm/lily.scm}.
-@node Output details
-@section Output details
-
-The default output format is La@TeX{}, which should be run
-through La@TeX{}. Using the option @option{-f}
-(or @option{--format}) other output formats can be selected also, but
-currently none of them work reliably.
-
-At the beginning of the output file, various global parameters are
-defined. Then the file @file{lilyponddefs.tex} is loaded to define
-the macros used in the code which follows. @file{lilyponddefs.tex}
-includes various other files, partially depending on the global
-parameters.
-
-Now the music is output system by system (a `system' consists of all
-staves belonging together). From @TeX{}'s point of view, a system is an
-@code{\hbox} which contains a lowered @code{\vbox} so that it is centered
-vertically on the baseline of the text. Between systems,
-@code{\interscoreline} is inserted vertically to have stretchable space.
-The horizontal dimension of the @code{\hbox} is given by the
-@code{linewidth} parameter from LilyPond's @code{\paper} block.
+@item
+A @code{\book} block logically combines multiple movements
+(ie. multiple @code{\score} blocks) into one document. A number of
+@code{\scores} creates a single output file, where all movement are
+concatenated..
-After the last system LilyPond emits a stronger variant of
-@code{\interscoreline} only if the macro
-@code{\lilypondpaperlastpagefill} is not defined (flushing the systems
-to the top of the page). You can avoid that by setting the variable
-@code{lastpagefill} in LilyPond's @code{\paper} block.
+This behavior can be changed by setting the variable
+@code{toplevel-book-handler} at toplevel. The default handler is
+defined in the init file @file{scm/lily.scm}.
-It is possible to fine-tune the vertical offset further by defining the
-macro @code{\lilypondscoreshift}:
+@item A compound music expression, such as
@example
-\def\lilypondscoreshift@{0.25\baselineskip@}
+ @{ c'4 d' e'2 @}
@end example
-@noindent
-where @code{\baselineskip} is the distance from one text line to the next.
-
-Here an example how to embed a small LilyPond file @code{foo.ly} into
-running La@TeX{} text without using the @code{lilypond-book} script
-(@pxref{lilypond-book manual}):
-
-@example
-\documentclass@{article@}
-
-\def\lilypondpaperlastpagefill@{@}
-\lineskip 5pt
-\def\lilypondscoreshift@{0.25\baselineskip@}
+This will add the piece in a @code{\score}, and formats it into a
+single book together with all other toplevel @code{\score}s and music
+expressions.
+
+This behavior can be changed by setting the variable
+@code{toplevel-music-handler} at toplevel. The default handler is
+defined in the init file @file{scm/lily.scm}.
+
+@end itemize
-\begin@{document@}
-This is running text which includes an example music file
-\input@{foo.tex@}
-right here.
-\end@{document@}
-@end example
+The following example shows three things which may be entered at
+toplevel
+@verbatim
+ \layout {
+ % movements are non-justified by default
+ raggedright = ##t
+ }
+
+ \header {
+ title = "Do-re-mi"
+ }
+
+ { c'4 d' e2 }
+@end verbatim
-The file @file{foo.tex} has been simply produced with
-@example
- lilypond-bin foo.ly
-@end example
+At any point in a file, any of the following lexical instructions can
+be entered:
-The call to @code{\lineskip} assures that there is enough vertical space
-between the LilyPond box and the surrounding text lines.
+@itemize @bullet
+@item @code{\version}
+@item @code{\include}
+@item @code{\encoding}
+@item @code{\renameinput}
+@end itemize
projects / lilypond.git / blobdiff