@c -*- coding: utf-8; mode: texinfo; -*-
+@c This file is part of lilypond.tely
+@ignore
+ Translation of GIT committish: FILL-IN-HEAD-COMMITTISH
+
+ When revising a translation, copy the HEAD committish of the
+ version that you are working on. See TRANSLATION for details.
+@end ignore
+
@node Changing defaults
@chapter Changing defaults
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
+number of proverbial @q{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
particular effect.
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/@/v2.8/@/Documentation/@/user/@/
-lilypond@/-internals/,on@/-line},
+@c leave the @uref as one long line.
+@uref{http://@/lilypond@/.org/@/doc/@/stable/@/Documentation/@/user/@/lilypond@/-internals/,on@/-line},
but is also included with the LilyPond documentation package.
There are four areas where the default settings may be changed:
notation. For example, giving each staff a separate time signature.
@item
-Global layout: changing the appearance of the spacing, line
+Page layout: changing the appearance of the spacing, line
breaks, and page dimensions. These modifications are discussed
-in @ref{Global issues}.
+in @ref{Non-musical notation}, and @ref{Spacing issues}.
@end itemize
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 short tutorial
+@code{#}.@footnote{@ref{Scheme tutorial}, contains a short tutorial
on entering numbers, lists, strings, and symbols in Scheme.}
Common rules for typesetting accidentals have been placed in a
function. This function is called as follows
-@cindex @code{set-accidental-style}
+@funindex set-accidental-style
+@example
+#(set-accidental-style 'STYLE)
+@end example
+
+@c TODO: check the context stuff below
+@c -does it *really* work?
+@c -the default contexts as specified in
+@c scm/music-function.scm seem to be different -vv
+
+Optionally, the function can take two arguments: the name of the
+accidental style, and an optional argument that denotes the context that
+should be changed:
+
@example
#(set-accidental-style 'STYLE #('CONTEXT#))
@end example
-The function can take two arguments: the name of the accidental style,
-and an optional argument that denotes the context that should be
-changed. If no context name is supplied, @code{Staff} is the default,
+If no context name is supplied, @code{Staff} is the default,
but you may wish to apply the accidental style to a single @code{Voice}
instead.
-@c TODO: we should create a very clear example, and show every
-@c accidental style on that example (with the example specially
-@c constructed so that it illustrates all the differences). -gp
+The following accidental styles are supported:
-The following accidental styles are supported
@table @code
@item default
This is the default typesetting behavior. It corresponds
remembered to the end of the measure in which they occur and
only on their own octave.
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ %#(set-accidental-style 'default)
+ \musicA }
+ \context Staff = "down"{
+ %#(set-accidental-style 'default)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'default" }}}
+}
+@end lilypond
+
@item voice
The normal behavior is to remember the accidentals on
Staff-level. This variable, however, typesets accidentals
individually for each voice. Apart from that, the rule is similar to
@code{default}.
+@example
+ \new Staff <<
+ #(set-accidental-style 'voice)
+ @{ @dots{} @}
+ >>
+@end example
+
As a result, accidentals from one voice do not get canceled in other
-voices, which is often an unwanted result
-
-@lilypond[quote,ragged-right,relative=1,fragment,verbatim]
-\new Staff <<
- #(set-accidental-style 'voice)
- <<
- { es g } \\
- { c, e }
->> >>
+voices, which is often an unwanted result: in the following example, it
+is hard to determine whether the second @samp{a} should be played
+natural or sharp.
+
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'voice)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'voice)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'voice" }}}
+}
@end lilypond
The @code{voice} option should be used if the voices
should be used instead.
@item modern
-@cindex @code{modern} style accidentals
+@funindex modern style accidentals
This rule corresponds to the common practice in the 20th century. This rule
prints the same accidentals as @code{default}, but temporary
accidentals also are canceled in other octaves. Furthermore,
in the same octave, they also get canceled in the following
-measure
+measure: in the following example, notice the two natural signs which appear
+in the second bar of the upper staff.
-@lilypond[quote,ragged-right,fragment,verbatim]
-#(set-accidental-style 'modern)
-cis' c'' cis'2 | c'' c'
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'modern)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'modern)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'modern" }}}
+}
@end lilypond
@item @code{modern-cautionary}
-@cindex @code{modern-cautionary}
-This rule is similar to @code{modern}, but the ``extra'' accidentals
+@funindex modern-cautionary
+This rule is similar to @code{modern}, but the @q{extra} accidentals
(the ones not typeset by @code{default}) are typeset as cautionary
-accidentals. They are printed in reduced size or with parentheses
-@lilypond[quote,ragged-right,fragment,verbatim]
-#(set-accidental-style 'modern-cautionary)
-cis' c'' cis'2 | c'' c'
+accidentals. They are printed in reduced size or (by default)
+with parentheses -- this can be set by definig the @code{cautionary-style}
+property of the @internalsref{AccidentalSuggestion} object.
+
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'modern-cautionary)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'modern-cautionary)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'modern-cautionary" }}}
+}
@end lilypond
-@cindex @code{modern-voice}
+@funindex modern-voice
@item modern-voice
This rule is used for multivoice accidentals to be read both by musicians
playing one voice and musicians playing all voices. Accidentals are
typeset for each voice, but they @emph{are} canceled across voices in
the same @internalsref{Staff}.
-@cindex @code{modern-voice-cautionary}
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'modern-voice)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'modern-voice)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'modern-voice" }}}
+}
+@end lilypond
+
+@funindex modern-voice-cautionary
@item modern-voice-cautionary
This rule is the same as @code{modern-voice}, but with the extra
accidentals (the ones not typeset by @code{voice}) typeset
@code{default} @emph{are} typeset by this variable,
some of them are typeset as cautionaries.
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'modern-voice-cautionary)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'modern-voice-cautionary)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'modern-voice-cautionary" }}}
+}
+@end lilypond
+
@item piano
-@cindex @code{piano} accidentals
-This rule reflects 20th century practice for piano notation. Very similar to
-@code{modern} but accidentals also get canceled
+@funindex piano accidentals
+This accidental style takes place in a GrandStaff context. However, you have to
+explicitly set it for @emph{each} individual Staff of the GrandStaff:
+
+@example
+\new GrandStaff @{ <<
+ \new Staff = "up" @{ <<
+ #(set-accidental-style 'piano)
+ @{ @dots{} @}
+ >> @}
+ \new Staff = "down"@{ <<
+ #(set-accidental-style 'piano)
+ @{ @dots{} @}
+ >> @}
+>> @}
+@end example
+
+This rule reflects 20th century practice for piano notation. Its behavior is very
+similar to @code{modern} style, but here accidentals also get canceled
across the staves in the same @internalsref{GrandStaff} or
@internalsref{PianoStaff}.
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'piano)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'piano)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'piano" }}}
+}
+@end lilypond
+
@item piano-cautionary
-@cindex @code{#(set-accidental-style 'piano-cautionary)}
+@funindex #(set-accidental-style 'piano-cautionary)
Same as @code{#(set-accidental-style 'piano)} but with the extra
accidentals typeset as cautionaries.
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'piano-cautionary)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'piano-cautionary)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'piano-cautionary" }}}
+}
+@end lilypond
+
@item no-reset
-@cindex @code{no-reset} accidental style
+@funindex no-reset accidental style
This is the same as @code{default} but with accidentals lasting
-``forever'' and not only until the next measure
-@lilypond[quote,ragged-right,fragment,verbatim,relative=1]
-#(set-accidental-style 'no-reset)
-c1 cis cis c
+@q{forever} and not only until the next measure:
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'no-reset)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'no-reset)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'no-reset" }}}
+}
@end lilypond
@item forget
This is sort of the opposite of @code{no-reset}: Accidentals
-are not remembered at all---and hence all accidentals are
+are not remembered at all -- and hence all accidentals are
typeset relative to the key signature, regardless of what was
before in the music
-@lilypond[quote,ragged-right,fragment,verbatim,relative=1]
-#(set-accidental-style 'forget)
-\key d\major c4 c cis cis d d dis dis
+@lilypond[quote,ragged-right]
+musicA = { << \relative { cis'8 fis, d'4 <a cis>8 f bis4 | cis2. <c, g'>4 | } \\
+ \relative { ais'2 cis, | fis8 b a4 cis2 | } >> }
+
+musicB = { \clef bass \new Voice { \voiceTwo \relative { < fis, a cis>4
+ \change Staff = up cis' \change Staff = down <fis, a>
+ \change Staff = up dis' | \change Staff = down <fis, a cis>4 gis
+ <f a d>2 | } }}
+
+\score {
+ \new PianoStaff {
+ << \context Staff = "up" {
+ #(set-accidental-style 'forget)
+ \musicA }
+ \context Staff = "down"{
+ #(set-accidental-style 'forget)
+ \musicB } >> }
+ \header { piece = \markup {\fill-line { \fontsize #3 "'forget" }}}
+}
@end lilypond
@end table
@seealso
Program reference: @internalsref{Accidental_engraver},
-@internalsref{Accidental}, and @internalsref{AccidentalPlacement}.
+@internalsref{Accidental}, @internalsref{AccidentalSuggestion} and @internalsref{AccidentalPlacement}.
@refbugs
@node Setting automatic beam behavior
@subsection Setting automatic beam behavior
-@cindex @code{autoBeamSettings}
-@cindex @code{(end * * * *)}
-@cindex @code{(begin * * * *)}
+@funindex autoBeamSettings
+@funindex (end * * * *)
+@funindex (begin * * * *)
@cindex automatic beams, tuning
@cindex tuning automatic beaming
3/8 and on the fourth beat of the measure (after 3/4, that is 2 times
3/8, has passed within the measure).
+If any unexpected beam behaviour occurs, check the default automatic beam
+settings in @file{scm/@/auto@/-beam@/.scm}
+for possible interference, because the beam
+endings defined there will still apply on top of your own overrides. Any
+unwanted endings in the default vales must be reverted for your time
+signature(s).
+
+For example, to typeset @code{(3 4 3 2)}-beam endings in 12/8, begin
+with
+
+@example
+%%% revert default values in scm/auto-beam.scm regarding 12/8 time
+#(revert-auto-beam-setting '(end * * 12 8) 3 8)
+#(revert-auto-beam-setting '(end * * 12 8) 3 4)
+#(revert-auto-beam-setting '(end * * 12 8) 9 8)
+
+%%% your new values
+#(override-auto-beam-setting '(end 1 8 12 8) 3 8)
+#(override-auto-beam-setting '(end 1 8 12 8) 7 8)
+#(override-auto-beam-setting '(end 1 8 12 8) 10 8)
+@end example
+
@cindex automatic beam generation
@cindex autobeam
-@cindex @code{autoBeaming}
+@funindex autoBeaming
@cindex lyrics
If beams are used to indicate melismata in songs, then automatic
@refcommands
-@cindex @code{\autoBeamOff}
+@funindex \autoBeamOff
@code{\autoBeamOff},
-@cindex @code{\autoBeamOn}
+@funindex \autoBeamOn
@code{\autoBeamOn}.
+@commonprop
+
+Beaming patterns may be altered with the @code{beatGrouping} property,
+
+@lilypond[quote,verbatim,relative=2,fragment,ragged-right]
+\time 5/16
+\set beatGrouping = #'(2 3)
+c8[^"(2+3)" c16 c8]
+\set beatGrouping = #'(3 2)
+c8[^"(3+2)" c16 c8]
+@end lilypond
+
@refbugs
* Layout tunings within contexts::
* Changing context default settings::
* Defining new contexts::
+* Aligning contexts::
+* Vertical grouping of grobs::
@end menu
@subsection Contexts explained
When music is printed, a lot of notational elements must be added to the
-input. For example, compare the input and output of the following example:
+output. For example, compare the input and output of the following example:
@lilypond[quote,verbatim,relative=2,fragment]
cis4 cis2. g4
@context{Score} can contain many @context{Staff} contexts.
@quotation
-@image{context-example,1600%,,eps}
+@image{context-example,5cm,,}
@end quotation
Each context has the responsibility for enforcing some notation rules,
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}
+@funindex \new
@cindex new contexts
@cindex Context, creating
context already earlier with the same name.
-@cindex @code{\context}
+@funindex \context
@item
Like @code{\new}, the @code{\context} command also directs a music
@code{\context}, it is usually applied to @context{Voice}
@example
-\applyOutput #@var{function} % apply to Voice
+\applyOutput #'@var{context} #@var{function} % apply to Voice
@end example
To have it interpreted at the @context{Score} or @context{Staff} level use
these forms
@example
-\context Score \applyOutput #@var{function}
-\context Staff \applyOutput #@var{function}
+\applyOutput #'Score #@var{function}
+\applyOutput #'Staff #@var{function}
@end example
@end itemize
@subsection Changing context properties on the fly
@cindex properties
-@cindex @code{\set}
+@funindex \set
@cindex changing properties
Each context can have different @emph{properties}, variables contained
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
+@q{on-the-fly}, during the music, so that the setting only affects the
second group of eighth notes.
-@cindex @code{\unset}
+@funindex \unset
There is also an @code{\unset} command,
@example
Notation contexts (like @code{Score} and @code{Staff}) not only
store properties,
-they also contain plug-ins called ``engravers'' that create notation
+they also contain plug-ins called @q{engravers} that create notation
elements. For example, the @code{Voice} context contains a
@code{Note_head_engraver} and the @code{Staff} context contains a
@code{Key_signature_engraver}.
starting a new context with @code{\new} or @code{\context}, and
modifying it,
-@cindex @code{\with}
+@funindex \with
@example
\new @var{context} \with @{
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
+formatting system (@q{grob property} or @q{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
+tweak}, explains what to fill in for @var{name}, @var{property}, and
@var{value}. Here we only discuss the functionality of this command.
The command
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
+causing the default context @context{Voice} to be used. Adding
+@code{\once} applies the change during one timestep only.
@lilypond[quote,fragment,verbatim,relative=2]
c4
\revert Staff.Stem #'thickness
@end example
-Some tweakable options are called ``subproperties'' and reside inside
+Some tweakable options are called @q{subproperties} and reside inside
properties. To tweak those, use commands of the form
@c leave this as a long long
@}
@end example
-Here @code{\Staff} takes the existing definition for context @context{Staff} from the
-identifier @code{\Staff}.
+The @code{\Staff} command brings in the existing definition of the
+staff context so that it can be modified.
The statements
@example
The @code{\RemoveEmptyStaffContext} will overwrite your current
@code{\Staff} settings. If you wish to change the defaults for a
staff which uses @code{\RemoveEmptyStaffContext}, you must do so
-after calling @code{\RemoveemptyStaffContext}, ie
+after calling @code{\RemoveEmptyStaffContext}, ie
@example
\layout @{
@}
@end example
-In the following discussion, the example input shown should go on the
-@dots{} in the previous fragment.
+In the following discussion, the example input shown should go in place
+of the @dots{} in the previous fragment.
-First the context's name is defined. Instead of @context{Voice} it
-will be called @context{ImproVoice},
+First it is necessary to define a name for the new context:
@example
\name ImproVoice
\alias Voice
@end example
-The context will print notes, and instructive texts
+The context will print notes and instructive texts, so we need to add
+the engravers which provide this functionality,
@example
\consists Note_heads_engraver
\consists Text_engraver
@end example
-but only on the center line,
+but we only need this on the center line,
@example
\consists Pitch_squash_engraver
@}
@end example
-@cindex @code{\accepts}
+@funindex \accepts
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}
@}
@end example
-@cindex @code{\denies}
+@funindex \denies
The opposite of @code{\accepts} is @code{\denies},
which is sometimes needed when reusing existing context definitions.
@end example
+@node Aligning contexts
+@subsection Aligning contexts
+
+New contexts may be aligned above or below exisiting contexts. This
+could be useful in setting up a vocal staff (@ref{Vocal ensembles}) and
+in ossia,
+
+@cindex ossia
+@findex alignAboveContext
+@findex alignBelowContext
+
+@lilypond[quote,ragged-right]
+ossia = { f4 f f f }
+\score{
+ \relative c' \new Staff = "main" {
+ c4 c c c
+ <<
+ \new Staff \with {alignAboveContext=main} \ossia
+ { d8 f d f d f d f }
+ >>
+ }
+}
+@end lilypond
+
+
+@node Vertical grouping of grobs
+@subsection Vertical grouping of grobs
+
+The VerticalAlignment and VerticalAxisGroup grobs work together.
+VerticalAxisGroup groups together different grobs like Staff, Lyrics,
+etc. VerticalAlignment then vertically aligns the different grobs
+grouped together by VerticalAxisGroup. There is usually only one
+VerticalAlignment per score but every Staff, Lyrics, etc. has its own
+VerticalAxisGroup.
@node The \override command
-@section The \override command
+@section The @code{\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 in more detail at how to use the command in practice.
+we will look in more detail at how to use the command in practice. The
+general syntax of this command is:
+
+@example
+\override @var{context}.@var{layout_object} #'@var{layout_property} = #@var{value}
+@end example
+This will set the @var{layout_property} of the specified @var{layout_object},
+which is a member of the @var{context}, to the @var{value}.
@menu
* Constructing a tweak::
* Layout interfaces::
* Determining the grob property::
* Objects connected to the input::
-* \set vs. \override::
+* Using Scheme code instead of \tweak::
+* \set versus \override::
* Difficult tweaks::
@end menu
@end example
@noindent
-This means that we must determine these bits of information:
+To construct this tweak we must determine these bits of information:
@itemize
@item the context: here @context{Voice}.
@item a sensible value: here @code{3.0}.
@end itemize
-Some tweakable options are called ``subproperties'' and reside inside
+Some tweakable options are called @q{subproperties} and reside inside
properties. To tweak those, use commands in the form
@example
@cindex finding graphical objects
@cindex graphical object descriptions
@cindex tweaking
-@cindex @code{\override}
+@funindex \override
@cindex internal documentation
+For many properties, regardless of the data type of the property, setting the
+property to false ( @code{##f} ) will result in turning it off, causing
+Lilypond to ignore that property entirely. This is particularly useful for
+turning off grob properties which may otherwise be causing problems.
+
We demonstrate how to glean this information from the notation manual
and the program reference.
+
+
@node Navigating the program reference
@subsection Navigating the program reference
manual.
@end ignore
+@ifnothtml
+The programmer's reference is available as an HTML document. It is
+highly recommended that you read it in HTML form, either online or
+by downloading the HTML documentation. This section will be much more
+difficult to understand if you are using the
+PDF manual.
+@end ifnothtml
+
Follow the link to @internalsref{Fingering}. At the top of the
page, you will see
@internalsref{New_fingering_engraver}.
@end quotation
-By clicking around in the program reference, we can follow the
-flow of information within the program, following links like this:
+By following related links inside the program reference, we can follow the
+flow of information within the program:
@itemize @bullet
@item @internalsref{Fingering}:
@internalsref{Fingering} objects are created by:
-@b{@internalsref{Fingering_engraver}}
+@internalsref{Fingering_engraver}
@item @internalsref{Fingering_engraver}:
-Music types accepted: @b{@internalsref{fingering-event}}
+Music types accepted: @internalsref{fingering-event}
@item @internalsref{fingering-event}:
Music event type @code{fingering-event} is in Music expressions named
-@b{@internalsref{FingerEvent}}
+@internalsref{FingerEvent}
@end itemize
This path goes against the flow of information in the program: it
@end quotation
@noindent
-which means that the number will be kept at a distance of at least 0.6
+which means that the number will be kept at a distance of at least 0.5
of the note head.
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
+them are not user-serviceable (@q{Internal properties}), but others
can be modified.
We have been talking of @emph{the} @code{Fingering} object, but actually it
does not amount to much. The initialization file (see
@ref{Default files})
-@file{scm/@/define@/-grobs@/.scm} shows the soul of the `object',
+@file{scm/@/define@/-grobs@/.scm} shows the soul of the @q{object},
@example
(Fingering
the @internalsref{Fingering_engraver} plug-in says
@quotation
-Fingering_engraver is part of contexts: @dots{} @b{@internalsref{Voice}}
+Fingering_engraver is part of contexts: @dots{} @internalsref{Voice}
@end quotation
@node Objects connected to the input
@subsection Objects connected to the input
-@cindex @code{\tweak}
+@funindex \tweak
In some cases, it is possible to take a short-cut for tuning graphical
-objects. For objects that result directly from a piece of the input,
+objects. For objects that result directly from a piece of the input,
you can use the @code{\tweak} function, for example
@lilypond[relative=2,fragment,verbatim,ragged-right]
>4-\tweak #'padding #10 -.
@end lilypond
-As you can see, properties are set directly in the objects directly,
+As you can see, properties are set in the objects directly,
without mentioning the grob name or context where this should be
applied.
This technique only works for objects that are directly connected to
-an @internalsref{event} from the input, for example
+an @internalsref{Event} from the input, for example
@itemize @bullet
-@item note heads, caused by chord-pitch (i.e., notes inside a chord).
-@item articulation signs, caused by articulation instructions.
+@item note heads, caused by chord-pitch (i.e., notes inside a chord)
+@item articulation signs, caused by articulation instructions
@end itemize
It notably does not work for stems and accidentals (these are caused
@end example
@noindent
-will not change color. See @ref{Displaying music expressions} for
+does not change color. See @ref{Displaying music expressions}, for
details.
-@node \set vs. \override
-@subsection \set vs. \override
+@node Using Scheme code instead of \tweak
+@subsection Using Scheme code instead of @code{\tweak}
+
+The main disadvantage of @code{\tweak} is its syntactical
+inflexibility. For example, the following produces a syntax error.
+
+@example
+F = \tweak #'font-size #-3 -\flageolet
+
+\relative c'' @{
+ c4^\F c4_\F
+@}
+@end example
+
+@noindent
+With other words, @code{\tweak} doesn't behave like an articulation
+regarding the syntax; in particular, it can't be attached with
+@samp{^} and @samp{_}.
+
+Using Scheme, this problem can be circumvented. The route to the
+result is given in @ref{Adding articulation to notes (example)},
+especially how to use @code{\displayMusic} as a helping guide.
+
+@example
+F = #(let ((m (make-music 'ArticulationEvent
+ 'articulation-type "flageolet")))
+ (set! (ly:music-property m 'tweaks)
+ (acons 'font-size -3
+ (ly:music-property m 'tweaks)))
+ m)
+
+\relative c'' @{
+ c4^\F c4_\F
+@}
+@end example
+
+@noindent
+Here, the @code{tweaks} properties of the flageolet object
+@samp{m} (created with @code{make-music}) are extracted with
+@code{ly:music-property}, a new key-value pair to change the
+font size is prepended to the property list with the
+@code{acons} Scheme function, and the result is finally
+written back with @code{set!}. The last element of the
+@code{let} block is the return value, @samp{m} itself.
+
+
+@node \set versus \override
+@subsection @code{\set} vs. @code{\override}
We have seen two methods of changing properties: @code{\set} and
@code{\override}. There are actually two different kinds of
There is a special type of context property: the element
description. These properties are named in @code{StudlyCaps}
(starting with capital letters). They contain the
-``default settings'' for said graphical object as an
+@q{default settings} for said graphical object as an
association list. See @file{scm/@/define@/-grobs@/.scm}
to see what kind of settings there are. Element descriptions
may be modified with @code{\override}.
The value of @code{context} (the alist) is used to initalize
the properties of individual grobs. Grobs also have
-properties, named in scheme style, with
+properties, named in Scheme style, with
@code{dashed-words}. The values of grob properties change
during the formatting process: formatting basically amounts
to computing properties using callback functions.
@item Some objects cannot be changed with @code{\override} for
-technical reasons. Examples of those are @code{NonMusicalPaperColumn}
+technical reasons. Examples of those are @code{NonMusicalPaperColumn}
and @code{PaperColumn}. They can be changed with the
-@code{\outputProperty} function, which works similar to @code{\once
-\override}, but uses a different syntax,
+@code{\overrideProperty} function, which works similar to @code{\once
+\override}, but uses a different syntax.
@example
-\outputProperty
+\overrideProperty
#"Score.NonMusicalPaperColumn" % Grob name
#'line-break-system-details % Property name
#'((next-padding . 20)) % Value
@end example
+Note, however, that @code{\override}, applied to
+@code{NoteMusicalPaperColumn} and @code{PaperColumn}, still works as
+expected within @code{\context} blocks.
+
@end itemize