1 @c -*- coding: utf-8; mode: texinfo; -*-
2 @c This file is part of lilypond.tely
4 Translation of GIT committish: FILL-IN-HEAD-COMMITTISH
6 When revising a translation, copy the HEAD committish of the
7 version that you are working on. See TRANSLATION for details.
12 @node Changing defaults
13 @chapter Changing defaults
15 The purpose of LilyPond's design is to provide the finest quality
16 output by default. Nevertheless, it may happen that you need to
17 change this default layout. The layout is controlled through a large
18 number of @q{knobs and switches} collectively called @q{properties}.
19 A tutorial introduction to accessing and modifying these properties
20 can be found in the Learning Manual, see @rlearning{Tweaking output}.
21 This should be read first. This chapter covers similar ground, but
22 in a style more appropriate to a reference manual.
24 @cindex Internals Reference
26 The definitive description of the controls available for tuning can
27 be found in a separate document: @rinternalsnamed{Top,the Internals
28 Reference}. That manual lists all the variables, functions and
29 options available in LilyPond. It is written as a HTML document,
31 @c leave the @uref as one long line.
32 @uref{http://@/lilypond@/.org/@/doc/@/stable/@/Documentation/@/user/@/lilypond@/-internals/,on@/-line},
33 and is also included with the LilyPond documentation package.
35 Internally, LilyPond uses Scheme (a LISP dialect) to provide
36 infrastructure. Overriding layout decisions in effect accesses the
37 program internals, which requires Scheme input. Scheme elements are
38 introduced in a @code{.ly} file with the hash mark
39 @code{#}.@footnote{@rlearning{Scheme tutorial}, contains a short tutorial
40 on entering numbers, lists, strings, and symbols in Scheme.}
44 * Interpretation contexts::
45 * Explaining the Internals Reference::
46 * Modifying properties::
47 * Useful concepts and properties::
52 @node Interpretation contexts
53 @section Interpretation contexts
55 This section describes what contexts are, and how to modify them.
58 * Contexts explained::
60 * Keeping contexts alive::
61 * Modifying context plug-ins::
62 * Changing context default settings::
63 * Defining new contexts::
70 @rlearning{Contexts and engravers}.
73 @file{ly/@/engraver@/-init@/.ly},
74 @file{ly/@/performer@/-init@/.ly}.
77 @rlsr{Contexts and engravers}.
80 @rinternals{Contexts},
81 @rinternals{Engravers and Performers}.
84 @node Contexts explained
85 @subsection Contexts explained
88 @c TODO Rethink and rewrite
90 >> > > - list of contexts: my *danger unmaintainable*
91 >> > > alarm just went off. I'm
93 I knew it would... And leaving out some of them is perfectly fine
95 I do think that a list like this, with the main contexts and a
97 description of what they do (perhaps also with a note about what
99 behavior is associated with each of them, but this may be
101 should be there, and then we could simply list the remaining ones
103 further explanation and with links to the IR.
106 @c TODO Improve layout, order and consistency of wording -td
108 @c TODO Add introduction which explains contexts in generality -td
110 @c TODO Describe propagation of property values -td
112 Contexts are arranged hierarchically:
115 * Score - the master of all contexts::
116 * Top-level contexts - staff containers::
117 * Intermediate-level contexts - staves::
118 * Bottom-level contexts - voices::
121 @node Score - the master of all contexts
122 @unnumberedsubsubsec Score - the master of all contexts
124 This is the top level notation context. No other context can
125 contain a Score context. By default the Score context handles
126 the administration of time signatures and makes sure that items
127 such as clefs, time signatures, and key-signatures are aligned
130 A Score context is instantiated implicitly when a
131 @code{\score @{@dots{}@}} or @code{\layout @{@dots{}@}} block is
132 processed, or explicitly when a @code{\new Score} command is
135 @node Top-level contexts - staff containers
136 @unnumberedsubsubsec Top-level contexts - staff containers
138 @strong{@emph{StaffGroup}}
140 Groups staves while adding a bracket on the left side, grouping
141 the staves together. The bar lines of the contained staves are
142 connected vertically. @code{StaffGroup} only consists of a collection
143 of staves, with a bracket in front and spanning bar lines.
145 @strong{@emph{ChoirStaff}}
147 Identical to @code{StaffGroup} except that the bar lines of the
148 contained staves are not connected vertically.
150 @strong{@emph{GrandStaff}}
152 A group of staves, with a brace on the left side, grouping the
153 staves together. The bar lines of the contained staves are
154 connected vertically.
156 @strong{@emph{PianoStaff}}
158 Just like @code{GrandStaff}, but with support for instrument names
159 to the left of each system.
161 @node Intermediate-level contexts - staves
162 @unnumberedsubsubsec Intermediate-level contexts - staves
164 @strong{@emph{Staff}}
166 Handles clefs, bar lines, keys, accidentals. It can contain
167 @code{Voice} contexts.
169 @strong{@emph{RhythmicStaff}}
171 Like @code{Staff} but for printing rhythms. Pitches are ignored;
172 the notes are printed on one line.
174 @strong{@emph{TabStaff}}
176 Context for generating tablature. By default lays the music
177 expression out as a guitar tablature, printed on six lines.
179 @strong{@emph{DrumStaff}}
181 Handles typesetting for percussion. Can contain @code{DrumVoice}
183 @strong{@emph{VaticanaStaff}}
185 Same as @code{Staff}, except that it is designed for typesetting
186 a piece in gregorian style.
188 @strong{@emph{MensuralStaff}}
190 Same as @code{Staff}, except that it is designed for typesetting
191 a piece in mensural style.
193 @node Bottom-level contexts - voices
194 @unnumberedsubsubsec Bottom-level contexts - voices
196 Voice-level contexts initialise certain properties and start
197 appropriate engravers. Being bottom-level contexts, they cannot
198 contain other contexts.
200 @strong{@emph{Voice}}
202 Corresponds to a voice on a staff. This context handles the
203 conversion of dynamic signs, stems, beams, super- and sub-scripts,
204 slurs, ties, and rests. You have to instantiate this explicitly
205 if you require multiple voices on the same staff.
207 @strong{@emph{VaticanaVoice}}
209 Same as @code{Voice}, except that it is designed for typesetting
210 a piece in gregorian style.
212 @strong{@emph{MensuralVoice}}
214 Same as @code{Voice}, with modifications for typesetting a piece in
217 @strong{@emph{Lyrics}}
219 Corresponds to a voice with lyrics. Handles the printing of a
220 single line of lyrics.
222 @strong{@emph{DrumVoice}}
224 The voice context used in a percussion staff.
226 @strong{@emph{FiguredBass}}
228 The context in which @code{BassFigure} objects are created from
229 input entered in @code{\figuremode} mode.
231 @strong{@emph{TabVoice}}
233 The voice context used within a @code{TabStaff} context. Usually
234 left to be created implicitly.
236 @strong{@emph{ChordNames}}
238 Typesets chord names.
243 Then the following, which I don't know what to do with:
245 * GregorianTranscriptionVoice
246 * GregorianTranscriptionStaff
249 Engraves fretboards from chords. Not easy... Not
251 There is now some documentation on FretBoards in the NR, under
252 instrument-specific notation -- cds.
256 * CueVoice Not documented
258 Hard coded entry point for LilyPond. Cannot be tuned.
260 Silently discards all musical information given to this
265 @node Creating contexts
266 @subsection Creating contexts
268 @c TODO \new Score and \score
269 @c TODO more complete descriptions rather than learning style
271 For scores with only one voice and one staff, contexts are
272 created automatically. For more complex scores, it is necessary to
273 create them by hand. There are three commands that do this.
278 The easiest command is @code{\new}, and it also the quickest to type.
279 It is prepended to a music expression, for example
283 @cindex Context, creating
286 \new @var{type} @var{music expression}
290 where @var{type} is a context name (like @code{Staff} or
291 @code{Voice}). This command creates a new context, and starts
292 interpreting the @var{music expression} with that.
294 A practical application of @code{\new} is a score with many
295 staves. Each part that should be on its own staff, is preceded with
298 @lilypond[quote,verbatim,relative=2,ragged-right,fragment]
305 The @code{\new} command may also give a name to the context,
308 \new @var{type} = @var{id} @var{music}
310 However, this user specified name is only used if there is no other
311 context already earlier with the same name.
317 Like @code{\new}, the @code{\context} command also directs a music
318 expression to a context object, but gives the context an explicit name. The
322 \context @var{type} = @var{id} @var{music}
325 This form will search for an existing context of type @var{type}
326 called @var{id}. If that context does not exist yet, a new
327 context with the specified name is created. This is useful if
328 the context is referred to later on. For example, when
329 setting lyrics the melody is in a named context
332 \context Voice = "@b{tenor}" @var{music}
336 so the texts can be properly aligned to its notes,
339 \new Lyrics \lyricsto "@b{tenor}" @var{lyrics}
344 Another possible use of named contexts is funneling two different
345 music expressions into one context. In the following example,
346 articulations and notes are entered separately,
350 arts = @{ s4-. s4-> @}
353 They are combined by sending both to the same @code{Voice} context,
357 \new Staff \context Voice = "A" \music
358 \context Voice = "A" \arts
361 @lilypond[quote,ragged-right]
365 \new Staff \context Voice = "A" \music
366 \context Voice = "A" \arts
370 With this mechanism, it is possible to define an Urtext (original
371 edition), with the option to put several distinct articulations on the
374 @cindex creating contexts
377 The third command for creating contexts is
379 \context @var{type} @var{music}
384 This is similar to @code{\context} with @code{= @var{id}}, but matches
385 any context of type @var{type}, regardless of its given name.
387 This variant is used with music expressions that can be interpreted at
388 several levels. For example, the @code{\applyOutput} command (see
389 @ref{Running a function on all layout objects}). Without an explicit
390 @code{\context}, it is usually applied to @code{Voice}
393 \applyOutput #'@var{context} #@var{function} % apply to Voice
396 To have it interpreted at the @code{Score} or @code{Staff} level use
400 \applyOutput #'Score #@var{function}
401 \applyOutput #'Staff #@var{function}
406 @node Keeping contexts alive
407 @subsection Keeping contexts alive
409 @cindex contexts, keeping alive
410 @cindex contexts, lifetime
412 Contexts are usually terminated at the first musical moment in
413 which they have nothing to do. So @code{Voice} contexts die as
414 soon as they contain no events; @code{Staff} contexts die as soon
415 as all the @code{Voice} contexts within them contain no events; etc.
416 This can cause difficulties if earlier contexts which have died
417 have to be referenced, for example, when changing staves with
418 @code{\change} commands, associating lyrics with a voice with
419 @code{\lyricsto} commands, or when adding further musical events to
422 There is an exception to this general rule: just one of the
423 @code{Voice} contexts in a @code{Staff} context or in a
424 @code{<<...>>} construct will always persist to the end of the
425 enclosing @code{Staff} context or @code{<<...>>} construct, even
426 though there may be periods when it has nothing to do. The context
427 to persist in this way will be the first one encountered in the
428 first enclosed @code{@{...@}} construct, ignoring any in enclosed
429 @code{<<...>>} constructs.
431 Any context can be kept alive by ensuring it has something to do at
432 every musical moment. @code{Staff} contexts are kept alive by
433 ensuring one of their voices is kept alive. One way of doing this
434 is to add spacer rests to a voice in parallel with the real music.
435 These need to be added to every @code{Voice} context which needs to
436 be kept alive. If several voices are to be used sporadically it is
437 safest to keep them all alive rather than attempting to rely on the
438 exceptions mentioned above.
440 In the following example, both voice A and voice B are kept alive
441 in this way for the duration of the piece:
443 @lilypond[quote,verbatim]
444 musicA = \relative c'' { d4 d d d }
445 musicB = \relative c'' { g4 g g g }
449 \new Voice = "A" { s1*5 } % Keep Voice "A" alive for 5 bars
450 \new Voice = "B" { s1*5 } % Keep Voice "B" alive for 5 bars
452 \context Voice = "A" {
456 \context Voice = "B" {
460 \context Voice = "A" {
461 % voiceOneStyle continues as Voice A is kept alive
464 \context Voice = "B" {
465 % voiceTwoStyle continues, as Voice "B" is kept alive
468 \context Voice = "A" {
469 % Voice "A" is still alive
478 @cindex lyrics, aligning with sporadic melody
480 The following example shows how a sporadic melody line with lyrics
481 might be written using this approach. In a real situation the
482 melody and accompaniment would consist of several different
485 @lilypond[quote,verbatim]
486 melody = \relative c'' { a4 a a a }
487 accompaniment = \relative c' { d4 d d d }
488 words = \lyricmode { These words con -- tain large gaps }
491 \new Staff = "music" {
493 \new Voice = "melody" {
495 s1*4 % Keep Voice "melody" alive for 4 bars
498 \new Voice = "accompaniment" {
503 \context Voice = "melody" { \melody }
504 \context Voice = "accompaniment" { \accompaniment }
506 \context Voice = "accompaniment" { \accompaniment }
508 \context Voice = "melody" { \melody }
509 \context Voice = "accompaniment" { \accompaniment }
514 \new Lyrics \with { alignAboveContext = #"music" }
515 \lyricsto "melody" { \words }
520 An alternative way, which may be better in many circumstances, is
521 to keep the melody line alive by simply include spacer notes to
522 line it up correctly with the accompaniment:
524 @lilypond[quote,verbatim]
525 melody = \relative c'' {
531 accompaniment = \relative c' {
537 words = \lyricmode { These words con -- tain large gaps }
541 \new Staff = "music" {
543 \new Voice = "melody" {
547 \new Voice = "accompaniment" {
553 \new Lyrics \with { alignAboveContext = #"music" }
554 \lyricsto "melody" { \words }
560 @node Modifying context plug-ins
561 @subsection Modifying context plug-ins
563 @c TODO Should this be Modifying engravers or Modifying contexts?
565 Notation contexts (like @code{Score} and @code{Staff}) not only
567 they also contain plug-ins called @q{engravers} that create notation
568 elements. For example, the @code{Voice} context contains a
569 @code{Note_head_engraver} and the @code{Staff} context contains a
570 @code{Key_signature_engraver}.
572 For a full a description of each plug-in, see
574 @rinternals{Engravers and Performers}.
577 Internals Reference @expansion{} Translation @expansion{} Engravers.
579 Every context described in
581 @rinternals{Contexts}
584 Internals Reference @expansion{} Translation @expansion{} Context.
586 lists the engravers used for that context.
589 It can be useful to shuffle around these plug-ins. This is done by
590 starting a new context with @code{\new} or @code{\context}, and
596 \new @var{context} \with @{
609 where the @dots{} should be the name of an engraver. Here is a simple
610 example which removes @code{Time_signature_engraver} and
611 @code{Clef_engraver} from a @code{Staff} context,
613 @lilypond[quote,relative=1,verbatim,fragment]
619 \remove "Time_signature_engraver"
620 \remove "Clef_engraver"
627 In the second staff there are no time signature or clef symbols. This
628 is a rather crude method of making objects disappear since it will affect
629 the entire staff. This method also influences the spacing, which may or
630 may not be desirable. More sophisticated methods of blanking objects
631 are shown in @rlearning{Visibility and color of objects}.
633 The next example shows a practical application. Bar lines and time
634 signatures are normally synchronized across the score. This is done
635 by the @code{Timing_translator} and @code{Default_bar_line_engraver}.
636 This plug-in keeps an administration of time signature, location
637 within the measure, etc. By moving these engraver from @code{Score} to
638 @code{Staff} context, we can have a score where each staff has its own
641 @cindex polymetric scores
642 @cindex Time signatures, multiple
644 @lilypond[quote,relative=1,ragged-right,verbatim,fragment]
646 \remove "Timing_translator"
647 \remove "Default_bar_line_engraver"
650 \consists "Timing_translator"
651 \consists "Default_bar_line_engraver"
657 \consists "Timing_translator"
658 \consists "Default_bar_line_engraver"
668 Usually the order in which the engravers are specified
669 does not matter, but in a few special cases the order
670 is important, for example where one engraver writes
671 a property and another reads it, or where one engraver
672 creates a grob and another must process it. The order in
673 which the engravers are specified is the order in which
674 they are called to carry out their processing.
676 The following orderings are important: the
677 @code{Bar_engraver} must normally be first, and
678 the @code{New_fingering_engraver} must come before
679 the @code{Script_column_engraver}. There may be others
680 with ordering dependencies.
682 @node Changing context default settings
683 @subsection Changing context default settings
685 The context settings which are to be used by default in
686 @code{Score}, @code{Staff} and @code{Voice} contexts may be specified
687 in a @code{\layout} block, as illustrated in the following example.
688 The @code{\layout} block should be placed within the @code{\score}
689 block to which it is to apply, but outside any music.
691 Note that the @code{\set} command itself and the context must be
692 omitted when the context default values are specified in this way:
694 @lilypond[quote,verbatim]
697 a4^"Really small, thicker stems, no time signature" a a a
704 \override Stem #'thickness = #4.0
705 \remove "Time_signature_engraver"
711 In this example, the @code{\Staff} command specifies that the
712 subsequent specifications are to be applied to all staves within
715 Modifications can be made to the @code{Score} context or all
716 @code{Voice} contexts in a similar way.
720 It is not possible to collect context changes in a variable and apply
721 them to a @code{\context} definition by referring to that variable.
723 The @code{\RemoveEmptyStaffContext} will overwrite your current
724 @code{\Staff} settings. If you wish to change the defaults for a
725 staff which uses @code{\RemoveEmptyStaffContext}, you must do so
726 after calling @code{\RemoveEmptyStaffContext}, ie
731 \RemoveEmptyStaffContext
733 \override Stem #'thickness = #4.0
738 @c TODO: add \with in here.
742 @node Defining new contexts
743 @subsection Defining new contexts
745 Specific contexts, like @code{Staff} and @code{Voice}, are made of
746 simple building blocks. It is possible to create new types of
747 contexts with different combinations of engraver plug-ins.
749 The next example shows how to build a different type of
750 @code{Voice} context from scratch. It will be similar to
751 @code{Voice}, but only prints centered slash note heads. It can be used
752 to indicate improvisation in jazz pieces,
754 @lilypond[quote,ragged-right]
757 \type "Engraver_group"
758 \consists "Note_heads_engraver"
759 \consists "Rhythmic_column_engraver"
760 \consists "Text_engraver"
761 \consists Pitch_squash_engraver
762 squashedPosition = #0
763 \override NoteHead #'style = #'slash
764 \override Stem #'transparent = ##t
768 \accepts "ImproVoice"
772 a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
773 c4 c^"undress" c_"while playing :)" c }
779 These settings are defined within a @code{\context} block inside a
780 @code{\layout} block,
790 In the following discussion, the example input shown should go in place
791 of the @dots{} in the previous fragment.
793 First it is necessary to define a name for the new context:
799 Since it is similar to the @code{Voice}, we want commands that work
800 on (existing) @code{Voice}s to remain working. This is achieved by
801 giving the new context an alias @code{Voice},
807 The context will print notes and instructive texts, so we need to add
808 the engravers which provide this functionality,
811 \consists Note_heads_engraver
812 \consists Text_engraver
815 but we only need this on the center line,
818 \consists Pitch_squash_engraver
819 squashedPosition = #0
822 The @rinternals{Pitch_squash_engraver} modifies note heads (created
823 by @rinternals{Note_heads_engraver}) and sets their vertical
824 position to the value of @code{squashedPosition}, in this case@tie{}@code{0},
827 The notes look like a slash, and have no stem,
830 \override NoteHead #'style = #'slash
831 \override Stem #'transparent = ##t
834 All these plug-ins have to cooperate, and this is achieved with a
835 special plug-in, which must be marked with the keyword @code{\type}.
836 This should always be @code{Engraver_group}.
839 \type "Engraver_group"
847 \type "Engraver_group"
848 \consists "Note_heads_engraver"
849 \consists "Text_engraver"
850 \consists Pitch_squash_engraver
851 squashedPosition = #0
852 \override NoteHead #'style = #'slash
853 \override Stem #'transparent = ##t
859 Contexts form hierarchies. We want to hang the @code{ImproVoice}
860 under @code{Staff}, just like normal @code{Voice}s. Therefore, we
861 modify the @code{Staff} definition with the @code{\accepts}
872 The opposite of @code{\accepts} is @code{\denies},
873 which is sometimes needed when reusing existing context definitions.
875 Putting both into a @code{\layout} block, like
885 \accepts "ImproVoice"
890 Then the output at the start of this subsection can be entered as
898 c c_"while playing :)"
905 @node Aligning contexts
906 @subsection Aligning contexts
908 New contexts may be aligned above or below existing contexts. This
909 could be useful in setting up a vocal staff (@rlearning{Vocal ensembles}) and
912 @c TODO Better example needed. Ref LM, and expand on it.
915 @funindex alignAboveContext
916 @funindex alignBelowContext
918 @lilypond[quote,ragged-right]
921 \relative c' \new Staff = "main" {
924 \new Staff \with { alignAboveContext = #"main" } \ossia
931 @cindex nested contexts
932 @cindex contexts, nested
937 Contexts like @code{PianoStaff} can contain other contexts
938 nested within them. Contexts which are acceptable for nesting
939 are defined by the @qq{accepts} list of a context. Contexts
940 which are not in this list are placed below the outer context
941 in the printed score.
942 For example, the @code{PianoStaff} context is defined by default
943 to accept @code{Staff} and @code{FiguredBass} contexts within
944 it, but not (for example) a @code{Lyrics} context. So in the
945 following structure the lyrics are placed below the piano staff
946 rather than between the two staves:
948 @lilypond[verbatim,quote,relative=1]
951 \new Staff { e4 d c2 }
952 \addlyrics { Three blind mice }
960 The @qq{accepts} list of a context can be modified to include
961 additional nested contexts, so if we wanted the lyrics to appear
962 between the two staves we could use:
964 @lilypond[verbatim,quote,relative=1]
965 \new PianoStaff \with { \accepts Lyrics }
967 \new Staff { e4 d c2 }
968 \addlyrics { Three blind mice }
976 The opposite of @code{\accepts} is @code{\denies}; this removes a
977 context from the @qq{accepts} list.
979 @node Explaining the Internals Reference
980 @section Explaining the Internals Reference
984 * Navigating the program reference::
985 * Layout interfaces::
986 * Determining the grob property::
987 * Naming conventions::
990 @node Navigating the program reference
991 @subsection Navigating the program reference
993 @c TODO remove this (it's in the LM)
994 @c Replace with more factual directions
996 Suppose we want to move the fingering indication in the fragment
999 @lilypond[quote,fragment,relative=2,verbatim]
1005 If you visit the documentation on fingering instructions (in
1006 @ref{Fingering instructions}), you will notice:
1011 Internals Reference: @rinternals{Fingering}.
1016 @c outdated info; probably will delete.
1018 This fragment points to two parts of the program reference: a page
1019 on @code{FingeringEvent} and one on @code{Fingering}.
1021 The page on @code{FingeringEvent} describes the properties of the music
1022 expression for the input @code{-2}. The page contains many links
1023 forward. For example, it says
1026 Accepted by: @rinternals{Fingering_engraver},
1030 That link brings us to the documentation for the Engraver, the
1034 This engraver creates the following layout objects: @rinternals{Fingering}.
1037 In other words, once the @code{FingeringEvent}s are interpreted, the
1038 @code{Fingering_engraver} plug-in will process them.
1042 @c I can't figure out what this is supposed to mean. -gp
1044 The @code{Fingering_engraver} is also listed to create
1045 @rinternals{Fingering} objects,
1047 @c old info? it doesn't make any sense to me with our current docs.
1049 second bit of information listed under @b{See also} in the Notation
1054 The programmer's reference is available as an HTML document. It is
1055 highly recommended that you read it in HTML form, either online or
1056 by downloading the HTML documentation. This section will be much more
1057 difficult to understand if you are using the
1061 Follow the link to @rinternals{Fingering}. At the top of the
1065 Fingering objects are created by: @rinternals{Fingering_engraver} and
1066 @rinternals{New_fingering_engraver}.
1069 By following related links inside the program reference, we can follow the
1070 flow of information within the program:
1074 @item @rinternals{Fingering}:
1075 @rinternals{Fingering} objects are created by:
1076 @rinternals{Fingering_engraver}
1078 @item @rinternals{Fingering_engraver}:
1079 Music types accepted: @rinternals{fingering-event}
1081 @item @rinternals{fingering-event}:
1082 Music event type @code{fingering-event} is in Music expressions named
1083 @rinternals{FingeringEvent}
1086 This path goes against the flow of information in the program: it
1087 starts from the output, and ends at the input event. You could
1088 also start at an input event, and read with the flow of
1089 information, eventually ending up at the output object(s).
1091 The program reference can also be browsed like a normal document. It
1092 contains chapters on
1094 @rinternals{Music definitions},
1097 @code{Music definitions}
1099 on @rinternals{Translation}, and the @rinternals{Backend}. Every
1100 chapter lists all the definitions used and all properties that may be
1104 @node Layout interfaces
1105 @subsection Layout interfaces
1107 @cindex interface, layout
1108 @cindex layout interface
1111 The HTML page that we found in the previous section describes the
1112 layout object called @rinternals{Fingering}. Such an object is a
1113 symbol within the score. It has properties that store numbers (like
1114 thicknesses and directions), but also pointers to related objects. A
1115 layout object is also called a @emph{Grob}, which is short for Graphical
1116 Object. For more details about Grobs, see @rinternals{grob-interface}.
1118 The page for @code{Fingering} lists the definitions for the
1119 @code{Fingering} object. For example, the page says
1122 @code{padding} (dimension, in staff space):
1128 which means that the number will be kept at a distance of at least 0.5
1132 Each layout object may have several functions as a notational or
1133 typographical element. For example, the Fingering object
1134 has the following aspects
1138 Its size is independent of the horizontal spacing, unlike slurs or beams.
1141 It is a piece of text. Granted, it is usually a very short text.
1144 That piece of text is typeset with a font, unlike slurs or beams.
1147 Horizontally, the center of the symbol should be aligned to the
1148 center of the note head.
1151 Vertically, the symbol is placed next to the note and the staff.
1154 The vertical position is also coordinated with other superscript
1155 and subscript symbols.
1158 Each of these aspects is captured in so-called @emph{interface}s,
1159 which are listed on the @rinternals{Fingering} page at the bottom
1162 This object supports the following interfaces:
1163 @rinternals{item-interface},
1164 @rinternals{self-alignment-interface},
1165 @rinternals{side-position-interface}, @rinternals{text-interface},
1166 @rinternals{text-script-interface}, @rinternals{font-interface},
1167 @rinternals{finger-interface}, and @rinternals{grob-interface}.
1170 Clicking any of the links will take you to the page of the respective
1171 object interface. Each interface has a number of properties. Some of
1172 them are not user-serviceable (@q{Internal properties}), but others
1175 We have been talking of @emph{the} @code{Fingering} object, but actually it
1176 does not amount to much. The initialization file (see
1177 @rlearning{Other sources of information})
1178 @file{scm/@/define@/-grobs@/.scm} shows the soul of the @q{object},
1183 (avoid-slur . around)
1184 (slur-padding . 0.2)
1185 (staff-padding . 0.5)
1186 (self-alignment-X . 0)
1187 (self-alignment-Y . 0)
1188 (script-priority . 100)
1189 (stencil . ,ly:text-interface::print)
1190 (direction . ,ly:script-interface::calc-direction)
1191 (font-encoding . fetaNumber)
1192 (font-size . -5) ; don't overlap when next to heads.
1193 (meta . ((class . Item)
1194 (interfaces . (finger-interface
1196 text-script-interface
1198 side-position-interface
1199 self-alignment-interface
1200 item-interface))))))
1204 As you can see, the @code{Fingering} object is nothing more than a
1205 bunch of variable settings, and the webpage in the Internals Reference
1206 is directly generated from this definition.
1209 @node Determining the grob property
1210 @subsection Determining the grob property
1212 @c TODO remove this (it's in the LM)
1213 @c Replace with more factual directions
1215 Recall that we wanted to change the position of the @b{2} in
1217 @lilypond[quote,fragment,relative=2,verbatim]
1223 Since the @b{2} is vertically positioned next to its note, we have to
1224 meddle with the interface associated with this positioning. This is
1225 done using @code{side-position-interface}. The page for this interface
1229 @code{side-position-interface}
1231 Position a victim object (this one) next to other objects (the
1232 support). The property @code{direction} signifies where to put the
1233 victim object relative to the support (left or right, up or down?)
1238 Below this description, the variable @code{padding} is described as
1243 (dimension, in staff space)
1245 Add this much extra space between objects that are next to each other.
1249 By increasing the value of @code{padding}, we can move the
1250 fingering away from the note head. The following command inserts
1251 3 staff spaces of white
1252 between the note and the fingering:
1254 \once \override Voice.Fingering #'padding = #3
1257 Inserting this command before the Fingering object is created,
1258 i.e., before @code{c2}, yields the following result:
1260 @lilypond[quote,relative=2,fragment,verbatim]
1261 \once \override Voice.Fingering #'padding = #3
1268 In this case, the context for this tweak is @code{Voice}. This
1269 fact can also be deduced from the program reference, for the page for
1270 the @rinternals{Fingering_engraver} plug-in says
1273 Fingering_engraver is part of contexts: @dots{} @rinternals{Voice}
1277 @node Naming conventions
1278 @subsection Naming conventions
1280 Another thing that is needed, is an overview of the various naming
1283 scheme functions: lowercase-with-hyphens (incl. one-word
1285 scheme functions: ly:plus-scheme-style
1286 music events, music classes and music properties:
1288 Grob interfaces: scheme-style
1289 backend properties: scheme-style (but X and Y!)
1290 contexts (and MusicExpressions and grobs): Capitalized or
1292 context properties: lowercaseFollowedByCamelCase
1294 Capitalized_followed_by_lowercase_and_with_underscores
1296 Which of these are conventions and which are rules?
1297 Which are rules of the underlying language, and which are
1301 @node Modifying properties
1302 @section Modifying properties
1304 @c TODO change the menu and subsection node names to use
1305 @c backslash once the new macro to handle the refs
1306 @c is available. Need to find and change all refs at
1307 @c the same time. -td
1310 * Overview of modifying properties::
1312 * The override command::
1313 * The tweak command::
1314 * set versus override::
1318 @node Overview of modifying properties
1319 @subsection Overview of modifying properties
1321 Each context is responsible for creating certain types of graphical
1322 objects. The settings used for printing these objects are also stored by
1323 context. By changing these settings, the appearance of objects can be
1326 The syntax for this is
1329 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1332 Here @var{name} is the name of a graphical object, like
1333 @code{Stem} or @code{NoteHead}, and @var{property} is an internal
1334 variable of the formatting system (@q{grob property} or @q{layout
1335 property}). The latter is a symbol, so it must be quoted. The
1336 subsection @ref{Modifying properties}, explains what to fill in
1337 for @var{name}, @var{property}, and @var{value}. Here we only
1338 discuss the functionality of this command.
1343 \override Staff.Stem #'thickness = #4.0
1347 makes stems thicker (the default is 1.3, with staff line thickness as a
1348 unit). Since the command specifies @code{Staff} as context, it only
1349 applies to the current staff. Other staves will keep their normal
1350 appearance. Here we see the command in action:
1352 @lilypond[quote,verbatim,relative=2,fragment]
1354 \override Staff.Stem #'thickness = #4.0
1360 The @code{\override} command changes the definition of the @code{Stem}
1361 within the current @code{Staff}. After the command is interpreted
1362 all stems are thickened.
1364 Analogous to @code{\set}, the @var{context} argument may be left out,
1365 causing the default context @code{Voice} to be used. Adding
1366 @code{\once} applies the change during one timestep only.
1368 @lilypond[quote,fragment,verbatim,relative=2]
1370 \once \override Stem #'thickness = #4.0
1375 The @code{\override} must be done before the object is
1376 started. Therefore, when altering @emph{Spanner} objects such as slurs
1377 or beams, the @code{\override} command must be executed at the moment
1378 when the object is created. In this example,
1380 @lilypond[quote,fragment,verbatim,relative=2]
1381 \override Slur #'thickness = #3.0
1383 \override Beam #'thickness = #0.6
1388 the slur is fatter but the beam is not. This is because the command for
1389 @code{Beam} comes after the Beam is started, so it has no effect.
1391 Analogous to @code{\unset}, the @code{\revert} command for a context
1392 undoes an @code{\override} command; like with @code{\unset}, it only
1393 affects settings that were made in the same context. In other words, the
1394 @code{\revert} in the next example does not do anything.
1397 \override Voice.Stem #'thickness = #4.0
1398 \revert Staff.Stem #'thickness
1401 Some tweakable options are called @q{subproperties} and reside inside
1402 properties. To tweak those, use commands of the form
1404 @c leave this as a long long
1406 \override @var{context}.@var{name} #'@var{property} #'@var{subproperty} = #@var{value}
1413 \override Stem #'(details beamed-lengths) = #'(4 4 3)
1418 Internals: @rinternals{OverrideProperty}, @rinternals{RevertProperty},
1419 @rinternals{PropertySet}, @rinternals{Backend}, and
1420 @rinternals{All layout objects}.
1425 The back-end is not very strict in type-checking object properties.
1426 Cyclic references in Scheme values for properties can cause hangs
1427 or crashes, or both.
1431 @node The set command
1432 @subsection The @code{\set} command
1436 @cindex changing properties
1438 Each context can have different @emph{properties}, variables contained
1439 in that context. They can be changed during the interpretation step.
1440 This is achieved by inserting the @code{\set} command in the music,
1443 \set @var{context}.@var{prop} = #@var{value}
1447 @lilypond[quote,verbatim,relative=2,fragment]
1449 \set Score.skipBars = ##t
1453 This command skips measures that have no notes. The result is that
1454 multi-rests are condensed. The value assigned is a Scheme object. In
1455 this case, it is @code{#t}, the boolean True value.
1457 If the @var{context} argument is left out, then the current bottom-most
1458 context (typically @code{ChordNames}, @code{Voice}, or
1459 @code{Lyrics}) is used. In this example,
1461 @lilypond[quote,verbatim,relative=2,fragment]
1463 \set autoBeaming = ##f
1468 the @var{context} argument to @code{\set} is left out, so automatic
1469 beaming is switched off in the current @rinternals{Voice}. Note that
1470 the bottom-most context does not always contain the property that you
1471 wish to change -- for example, attempting to set the @code{skipBars}
1472 property (of the bottom-most context, in this case @code{Voice}) will
1475 @lilypond[quote,verbatim,relative=2,fragment]
1481 Contexts are hierarchical, so if a bigger context was specified, for
1482 example @code{Staff}, then the change would also apply to all
1483 @code{Voice}s in the current stave. The change is applied
1484 @q{on-the-fly}, during the music, so that the setting only affects the
1485 second group of eighth notes.
1489 There is also an @code{\unset} command,
1491 \unset @var{context}.@var{prop}
1495 which removes the definition of @var{prop}. This command removes
1496 the definition only if it is set in @var{context}, so
1499 \set Staff.autoBeaming = ##f
1503 introduces a property setting at @code{Staff} level. The setting also
1504 applies to the current @code{Voice}. However,
1507 \unset Voice.autoBeaming
1511 does not have any effect. To cancel this setting, the @code{\unset}
1512 must be specified on the same level as the original @code{\set}. In
1513 other words, undoing the effect of @code{Staff.autoBeaming = ##f}
1516 \unset Staff.autoBeaming
1519 Like @code{\set}, the @var{context} argument does not have to be
1520 specified for a bottom context, so the two statements
1523 \set Voice.autoBeaming = ##t
1524 \set autoBeaming = ##t
1532 Settings that should only apply to a single time-step can be entered
1533 with @code{\once}, for example in
1535 @lilypond[quote,verbatim,relative=2,fragment]
1537 \once \set fontSize = #4.7
1542 the property @code{fontSize} is unset automatically after the second
1545 A full description of all available context properties is in the
1546 program reference, see
1548 @rinternals{Tunable context properties}.
1551 Translation @expansion{} Tunable context properties.
1556 @node The override command
1557 @subsection The @code{\override} command
1559 Commands which change output generally look like
1562 \override Voice.Stem #'thickness = #3.0
1566 To construct this tweak we must determine these bits of information:
1569 @item the context: here @code{Voice}.
1570 @item the layout object: here @code{Stem}.
1571 @item the layout property: here @code{thickness}.
1572 @item a sensible value: here @code{3.0}.
1575 Some tweakable options are called @q{subproperties} and reside inside
1576 properties. To tweak those, use commands in the form
1579 \override Stem #'(details beamed-lengths) = #'(4 4 3)
1582 @cindex internal documentation
1583 @cindex finding graphical objects
1584 @cindex graphical object descriptions
1587 @cindex internal documentation
1589 For many properties, regardless of the data type of the property, setting the
1590 property to false ( @code{##f} ) will result in turning it off, causing
1591 LilyPond to ignore that property entirely. This is particularly useful for
1592 turning off grob properties which may otherwise be causing problems.
1594 We demonstrate how to glean this information from the notation manual
1595 and the program reference.
1598 @node The tweak command
1599 @subsection The @code{\tweak} command
1604 In some cases, it is possible to take a short-cut for tuning
1605 graphical objects. For objects that are created directly from
1606 an item in the input file, you can use the @code{\tweak} command.
1609 @lilypond[relative=2,verbatim]
1614 \tweak #'duration-log #1
1617 -\tweak #'padding #8
1621 @cindex chord, modifying one note in
1623 But the main use of the @code{\tweak} command is to modify just
1624 one of a number of notation elements which start at the same musical
1625 moment, like the notes of a chord, or tuplet brackets which start
1628 For an introduction to the syntax and uses of the tweak command
1629 see @rlearning{Tweaking methods}.
1631 The @code{\tweak} command sets a property in the following object
1632 directly, without requiring the grob name or context to be
1633 specified. For this to work, it is necessary for the @code{\tweak}
1634 command to remain immediately adjacent to the object to which it is
1635 to apply after the input file has been converted to a music stream.
1636 This is often not the case, as many additional elements are inserted
1637 into the music stream implicitly. For example, when a note which is
1638 not part of a chord is processed, Lilypond implicitly inserts a
1639 @code{ChordEvent} event before the note, so separating the tweak
1640 from the note. However, if chord symbols are placed round the
1641 tweak and the note, the @code{\tweak} command comes after the
1642 @code{ChordEvent} in the music stream, so remaining adjacent to the
1643 note, and able to modify it.
1647 @lilypond[relative=2,verbatim,quote]
1648 <\tweak #'color #red c>4
1654 @lilypond[relative=2,verbatim,quote]
1655 \tweak #'color #red c4
1658 When several similar items are placed at the same musical moment,
1659 the @code{\override} command cannot be used to modify just one of
1660 them -- this is where the @code{\tweak} command must be used.
1661 Items which may appear more than once at the same musical moment
1662 include the following:
1664 @c TODO expand to include any further uses of \tweak
1666 @item note heads of notes inside a chord
1667 @item articulation signs on a single note
1668 @item ties between notes in a chord
1669 @item tuplet brackets starting at the same time
1672 @c TODO add examples of these
1675 and @code{\tweak} may be used to modify any single occurrence of
1678 Notably the @code{\tweak} command cannot be used to modify stems,
1679 beams or accidentals, since these are generated later by note heads,
1680 rather than by music elements in the input stream. Nor can a
1681 @code{\tweak} command be used to modify clefs or time signatures,
1682 since these become separated from any preceding @code{\tweak}
1683 command in the input stream by the automatic insertion of extra
1684 elements required to specify the context.
1686 But the @code{\tweak} command can be used as an alternative to
1687 the @code{\override} command to modify those notational elements
1688 that do not cause any additional implicit elements to be added
1689 before them in the music stream. For example, slurs may be
1690 modified in this way:
1692 @lilypond[verbatim,quote,relative=1]
1693 c-\tweak #'thickness #5 ( d e f)
1696 Also several @code{\tweak} commands may be placed before a
1697 notational element -- all affect it:
1699 @lilypond[verbatim,quote,relative=1]
1701 -\tweak #'style #'dashed-line
1702 -\tweak #'dash-fraction #0.2
1703 -\tweak #'thickness #3
1704 -\tweak #'color #red
1709 The music stream which is generated from a section of an input file,
1710 including any automatically inserted elements, may be examined,
1711 see @ref{Displaying music expressions}. This may be helpful in
1712 determining what may be modified by a @code{\tweak} command.
1717 @rlearning{Tweaking methods}.
1720 @ref{Displaying music expressions}.
1725 @cindex tweaks in a variable
1726 The @code{\tweak} command cannot be used inside a variable.
1728 @cindex tweaks in lyrics
1729 The @code{\tweak} commands cannot be used in @code{\lyricmode}.
1731 @cindex tweaking control points
1732 @cindex control points, tweaking
1734 The @code{\tweak} command cannot be used to modify the control
1735 points of just one of several ties in a chord, other than the first
1736 one encountered in the input file.
1738 @node set versus override
1739 @subsection @code{\set} vs. @code{\override}
1741 We have seen two methods of changing properties: @code{\set} and
1742 @code{\override}. There are actually two different kinds of
1745 Contexts can have properties, which are usually named in
1746 @code{studlyCaps}. They mostly control the translation from
1747 music to notation, eg. @code{localKeySignature} (for determining
1748 whether to print accidentals), @code{measurePosition} (for
1749 determining when to print a bar line). Context properties can
1750 change value over time while interpreting a piece of music;
1751 @code{measurePosition} is an obvious example of
1752 this. Context properties are modified with @code{\set}.
1754 There is a special type of context property: the element
1755 description. These properties are named in @code{StudlyCaps}
1756 (starting with capital letters). They contain the
1757 @q{default settings} for said graphical object as an
1758 association list. See @file{scm/@/define@/-grobs@/.scm}
1759 to see what kind of settings there are. Element descriptions
1760 may be modified with @code{\override}.
1762 @code{\override} is actually a shorthand;
1765 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1769 is more or less equivalent to
1771 @c leave this long line -gp
1773 \set @var{context}.@var{name} #'@var{property} = #(cons (cons '@var{property} @var{value}) <previous value of @var{context})
1776 The value of @code{context} (the alist) is used to initialize
1777 the properties of individual grobs. Grobs also have
1778 properties, named in Scheme style, with
1779 @code{dashed-words}. The values of grob properties change
1780 during the formatting process: formatting basically amounts
1781 to computing properties using callback functions.
1783 @code{fontSize} is a special property: it is equivalent to
1784 entering @code{\override ... #'font-size} for all pertinent
1785 objects. Since this is a common change, the special
1786 property (modified with @code{\set}) was created.
1789 @node Useful concepts and properties
1790 @section Useful concepts and properties
1795 * Direction and placement::
1796 * Distances and measurements::
1797 * Staff symbol properties::
1799 * Visibility of objects::
1801 * Rotating objects::
1805 @subsection Input modes
1807 The way in which the notation contained within an input file is
1808 interpreted is determined by the current input mode.
1812 This is activated with the @code{\chordmode} command, and causes
1813 input to be interpreted with the syntax of chord notation, see
1814 @ref{Chord notation}. Chords are rendered as notes on a staff.
1816 Chord mode is also activated with the @code{\chords} command.
1817 This also creates a new @code{ChordNames} context and
1818 causes the following input to be interpreted with the syntax of
1819 chord notation and rendered as chord names in the @code{ChordNames}
1820 context, see @ref{Printing chord names}.
1824 This is activated with the @code{\drummode} command, and causes
1825 input to be interpreted with the syntax of drum notation, see
1826 @ref{Basic percussion notation}.
1828 Drum mode is also activated with the @code{\drums} command.
1829 This also creates a new @code{DrumStaff} context and causes the
1830 following input to be interpreted with the syntax of drum notation
1831 and rendered as drum symbols on a drum staff, see @ref{Basic
1832 percussion notation}.
1834 @strong{Figure mode}
1836 This is activated with the @code{\figuremode} command, and causes
1837 input to be interpreted with the syntax of figured bass, see
1838 @ref{Entering figured bass}.
1840 Figure mode is also activated with the @code{\figures} command.
1841 This also creates a new @code{FiguredBass} context and causes the
1842 following input to be interpreted with the figured bass syntax
1843 and rendered as figured bass symbols in the @code{FiguredBass}
1844 context, see @ref{Introduction to figured bass}.
1846 @strong{Fret and tab modes}
1848 There are no special input modes for entering fret and tab symbols.
1850 To create tab diagrams, enter notes or chords in note mode and
1851 render them in a @code{TabStaff} context, see
1852 @ref{Default tablatures}.
1854 To create fret diagrams above a staff, you have two choices.
1855 You can either use the @code{FretBoards} context (see
1856 @ref{Automatic fret diagrams} or you can enter them as a markup
1857 above the notes using the @code{\fret-diagram} command (see
1858 @ref{Fret diagram markups}).
1860 @strong{Lyrics mode}
1862 This is activated with the @code{\lyricmode} command, and causes
1863 input to be interpreted as lyric syllables with optional durations
1864 and associated lyric modifiers, see @ref{Vocal music}.
1866 Lyric mode is also activated with the @code{\addlyrics} command.
1867 This also creates a new @code{Lyrics} context and an implicit
1868 @code{\lyricsto} command which associates the following lyrics
1869 with the preceding music.
1871 @strong{Markup mode}
1873 This is activated with the @code{\markup} command, and causes
1874 input to be interpreted with the syntax of markup, see
1875 @ref{Text markup commands}.
1877 @c silly work-around for texinfo broken-ness
1878 @c (@strong{Note...} causes a spurious cross-reference in Info)
1881 This is the default mode or it may be activated with the
1882 @code{\notemode} command. Input is interpreted as pitches,
1883 durations, markup, etc and typeset as musical notation on a staff.
1885 It is not normally necessary to specify note mode explicitly, but
1886 it may be useful to do so in certain situations, for example if you
1887 are in lyric mode, chord mode or any other mode and want to insert
1888 something that only can be done with note mode syntax.
1890 For example, to indicate dynamic markings for the verses of a
1891 choral pieces it is necessary to enter note mode to interpret
1894 @lilypond[verbatim,relative=2,quote]
1897 \notemode{\set stanza = \markup{ \dynamic f 1. } }
1901 \notemode{\set stanza = \markup{ \dynamic p 2. } }
1908 @node Direction and placement
1909 @subsection Direction and placement
1911 In typesetting music the direction and placement of many items is
1912 a matter of choice. For example, the stems of notes can
1913 be directed up or down; lyrics, dynamics, and other expressive
1914 marks may be placed above or below the staff; text may be aligned
1915 left, right or center; etc. Most of these choices may be left to
1916 be determined automatically by LilyPond, but in some cases it may
1917 be desirable to force a particular direction or placement.
1919 @strong{Default actions}
1921 By default some directions are always up or always down (e.g.
1922 dynamics or fermata), while other things can alternate between
1923 up or down based on the stem direction (like slurs or accents).
1925 @c TODO Add table showing these
1927 @strong{Context layout order}
1929 Contexts are normally positioned in a system from top to bottom
1930 in the order in which they are encountered. Note, however, that
1931 a context will be created implicitly if a command is encountered
1932 when there is no suitable context available to contain it. When
1933 contexts are nested, the outer context will exclude inner contexts
1934 which are not included in its @qq{accepts} list; excluded contexts
1935 will be repositioned below the outer context.
1937 The default order in which contexts are laid out and the
1938 @qq{accepts} list can be changed, see @ref{Aligning contexts}.
1940 @strong{Articulation direction indicators}
1942 When adding articulations to notes the direction indicator,
1943 @code{^} (meaning @qq{up}), @code{_} (meaning @qq{down}) or
1944 @code{-} (meaning @qq{use default direction}), can usually be
1945 omitted, in which case @code{-} is assumed. But a direction
1946 indicator is @strong{always} required before
1949 @item @code{\tweak} commands
1950 @item @code{\markup} commands
1951 @item @code{\tag} commands
1952 @item string markups, e.g. -"string"
1953 @item fingering instructions, e.g. @code{-1}
1954 @item articulation shortcuts, e.g. @code{-.}, @code{->}, @code{--}
1957 @strong{The direction property}
1959 The position or direction of many layout objects is controlled
1960 by the @code{direction} property.
1962 The value of the @code{direction} property may be
1963 set to @code{1}, meaning @qq{up} or @qq{above}, or to @code{-1},
1964 meaning @qq{down} or @qq{below}. The symbols @code{UP} and
1965 @code{DOWN} may be used instead of @code{1} and @code{-1}
1966 respectively. The default direction may be specified by setting
1967 @code{direction} to @code{0} or @code{CENTER}. Alternatively,
1968 in many cases predefined commands
1969 exist to specify the direction. These are all of the form
1972 @code{\xxxUp}, @code{xxxDown}, @code{xxxNeutral}
1975 where @code{xxxNeutral} means @qq{use the default direction}.
1976 See @rlearning{Within-staff objects}.
1978 In a few cases, arpeggio being the only common example, the value
1979 of the @code{direction} property specifies whether the object
1980 is to be placed to the right or left of the parent object. In
1981 this case @code{-1} or @code{LEFT} means @qq{to the left} and
1982 @code{1} or @code{RIGHT} means @qq{to the right}. @code{0}
1983 or @code{CENTER} means @qq{use the default} direction, as before.
1986 These all have side-axis set to #X
1987 AmbitusAccidental - direction has no effect
1989 StanzaNumber - not tried
1990 TrillPitchAccidental - not tried
1991 TrillPitchGroup - not tried
1996 @node Distances and measurements
1997 @subsection Distances and measurements
1999 @cindex distances, absolute
2000 @cindex distances, scaled
2007 Distances in LilyPond are of two types: absolute and scaled.
2009 Absolute distances are used for specifying margins, indents, and
2010 other page layout details, and are by default specified in
2011 millimeters. Distances may be specified in other units by
2012 following the quantity by @code{\mm}, @code{\cm},
2013 @code{\in}@tie{}(inches), or @code{\pt}@tie{}(points, 1/72.27
2014 of an inch). Page layout distances can also be specified in
2015 scalable units (see the following paragraph) by appending
2016 @code{\staff-space} to the quantity.
2017 Page layout is described in detail in @ref{Page formatting}.
2019 Scaled distances are always specified in units of the staff-space
2020 or, rarely, the half staff-space. The staff-space is the distance
2021 between two adjacent staff lines. The default value can be changed
2022 globally by setting the global staff size, or it can be overridden
2023 locally by changing the @code{staff-space} property of
2024 @code{StaffSymbol}. Scaled distances automatically scale with any
2025 change to the either the global staff size or the
2026 @code{staff-space} property of @code{StaffSymbol}, but fonts scale
2027 automatically only with changes to the global staff size.
2028 The global staff size thus enables the overall size of a rendered
2029 score to be easily varied. For the methods of setting the global
2030 staff size see @ref{Setting the staff size}.
2034 If just a section of a score needs to be rendered to a different
2035 scale, for example an ossia section or a footnote, the global staff
2036 size cannot simply be changed as this would affect the entire score.
2037 In such cases the change in size is made by overriding both the
2038 @code{staff-space} property of @code{StaffSymbol} and the size of
2039 the fonts. A Scheme function, @code{magstep}, is available to
2040 convert from a font size change to the equivalent change in
2041 @code{staff-space}. For an explanation and an example of its use,
2042 see @rlearning{Length and thickness of objects}.
2047 @rlearning{Length and thickness of objects}.
2050 @ref{Page formatting},
2051 @ref{Setting the staff size}.
2054 @node Staff symbol properties
2055 @subsection Staff symbol properties
2057 @cindex adjusting staff symbol
2058 @cindex drawing staff symbol
2059 @cindex staff symbol, setting of
2061 @c TODO Extend or remove this section. See also NR 1.6.2 Staff symbol
2062 @c Need to think of uses for these properties. Eg 'line-positions
2063 @c is used in a snippet to thicken centre line.
2064 @c If retained, add @ref to here in 1.6.2 -td
2066 The vertical position of staff lines and the number of staff lines
2067 can be defined at the same time. As the following example shows,
2068 note positions are not influenced by the staff line positions.
2070 @warning{The @code{'line-positions} property overrides the
2071 @code{'line-count} property. The number of staff lines is
2072 implicitly defined by the number of elements in the list of values
2073 for @code{'line-positions}.}
2075 @lilypond[verbatim,quote,relative=1]
2077 \override StaffSymbol #'line-positions = #'(7 3 0 -4 -6 -7)
2082 The width of a staff can be modified. The units are staff
2083 spaces. The spacing of objects inside the staff is not affected by
2086 @lilypond[verbatim,quote,relative=1]
2088 \override StaffSymbol #'width = #23
2095 @subsection Spanners
2097 Many objects of musical notation extend over several notes or even
2098 several bars. Examples are slurs, beams, tuplet brackets, volta
2099 repeat brackets, crescendi, trills, and glissandi. Such objects
2100 are collectively called @qq{spanners}, and have special properties to control
2101 their appearance and behaviour. Some of these properties are common
2102 to all spanners; others are restricted to a sub-set of the spanners.
2104 All spanners support the @code{spanner-interface}. A few, esentially
2105 those that draw a straight line between the two objects, support in
2106 addition the @code{line-spanner-interface}.
2108 @unnumberedsubsubsec Using the @code{spanner-interface}
2110 This interface provides two properties that apply to several spanners.
2112 @strong{@i{The @code{minimum-length} property}}
2114 The minimum length of the spanner is specified by the
2115 @code{minimum-length} property. Increasing this usually has the
2116 necessary effect of increasing the spacing of the notes between the
2117 two end points. However, this override has no effect on
2118 many spanners, as their length is determined by other considerations.
2119 A few examples where it is effective are shown below.
2129 Works as long as callback is made:
2133 Works not at all for:
2142 @lilypond[verbatim,quote,relative=2]
2145 % increase the length of the tie
2146 -\tweak #'minimum-length #5
2150 @lilypond[verbatim,quote,relative=2]
2152 \compressFullBarRests
2154 % increase the length of the rest bar
2155 \once \override MultiMeasureRest #'minimum-length = #20
2160 @lilypond[verbatim,quote,relative=2]
2162 % increase the length of the hairpin
2163 \override Hairpin #'minimum-length = #20
2167 This override can also be used to increase the length of slurs and
2170 @lilypond[verbatim,quote,relative=2]
2173 -\tweak #'minimum-length #5
2178 -\tweak #'minimum-length #5
2182 For some layout objects, the @code{minimum-length} property becomes
2183 effective only if the @code{set-spacing-rods} procedure is called
2184 explicitly. To do this, the @code{springs-and-rods} property should
2185 be set to @code{ly:spanner::set-spacing-rods}. For example,
2186 the minimum length of a glissando has no effect unless the
2187 @code{springs-and-rods} property is set:
2189 @lilypond[verbatim,quote,relative=1]
2193 % not effective alone
2194 \once \override Glissando #'minimum-length = #20
2197 % effective only when both overrides are present
2198 \once \override Glissando #'minimum-length = #20
2199 \once \override Glissando #'springs-and-rods = #ly:spanner::set-spacing-rods
2203 The same is true of the @code{Beam} object:
2205 @lilypond[verbatim,quote,relative=1]
2206 % not effective alone
2207 \once \override Beam #'minimum-length = #20
2210 % effective only when both overrides are present
2211 \once \override Beam #'minimum-length = #20
2212 \once \override Beam #'springs-and-rods = #ly:spanner::set-spacing-rods
2216 @strong{@i{The @code{to-barline} property}}
2218 The second useful property of the @code{spanner-interface} is
2219 @code{to-barline}. By default this is true, causing hairpins and
2220 other spanners which are terminated on the first note of a measure to
2221 end instead on the immediately preceding bar line. If set to false,
2222 the spanner will extend beyond the bar line and end on the note
2225 @lilypond[verbatim,quote,relative=2]
2226 a \< a a a a \! a a a \break
2227 \override Hairpin #'to-barline = ##f
2228 a \< a a a a \! a a a
2231 This property is not effective for all spanners. For example,
2232 seting it to @code{#t} has no effect on slurs or phrasing slurs
2233 or on other spanners for which terminating on the bar line would
2236 @unnumberedsubsubsec Using the @code{line-spanner-interface}
2238 Objects which support the @code{line-spanner-interface} include
2241 @item @code{DynamicTextSpanner}
2242 @item @code{Glissando}
2243 @item @code{TextSpanner}
2244 @item @code{TrillSpanner}
2245 @item @code{VoiceFollower}
2248 The routine responsible for drawing the stencils for these spanners is
2249 @code{ly:line-interface::print}. This routine determines the
2250 exact location of the two end points and draws a line
2251 between them, in the style requested. The locations of the two
2252 end points of the spanner are computed on-the-fly, but it is
2253 possible to override their Y-coordinates. The
2254 properties which need to be specified are nested
2255 two levels down within the property hierarchy, but the syntax of
2256 the @code{\override} command is quite simple:
2258 @lilypond[relative=2,quote,verbatim]
2260 \once \override Glissando #'(bound-details left Y) = #3
2261 \once \override Glissando #'(bound-details right Y) = #-2
2265 The units for the @code{Y} property are @code{staff-space}s,
2266 with the center line of the staff being the zero point.
2267 For the glissando, this is the value for @code{Y} at the
2268 X-coordinate corresponding to the center point of each note head,
2269 if the line is imagined to be extended to there.
2271 If @code{Y} is not set, the value is computed from the vertical
2272 position of the corresponding attachment point of the spanner.
2274 In case of a line break, the values for the end points are
2275 specified by the @code{left-broken} and @code{right-broken}
2276 sub-lists of @code{bound-details}. For example:
2278 @lilypond[relative=2,ragged-right,verbatim,fragment]
2279 \override Glissando #'breakable = ##t
2280 \override Glissando #'(bound-details right-broken Y) = #-3
2281 c1 \glissando \break
2286 A number of further properties of the @code{left} and
2287 @code{right} sub-lists of the @code{bound-details} property
2288 may be modified in the same way as @code{Y}:
2292 This sets the Y-coordinate of the end point, in @code{staff-space}s
2293 offset from the staff center line. By default, it is the center of
2294 the bound object, so a glissando points to the vertical center of
2297 For horizontal spanners, such as text spanners and trill spanners,
2298 it is hardcoded to 0.
2301 This determines where the line starts and ends in the X-direction,
2302 relative to the bound object. So, a value of @code{-1} (or
2303 @code{LEFT}) makes the line start/end at the left side of the note
2304 head it is attached to.
2307 This is the absolute X-coordinate of the end point. It is usually
2308 computed on the fly, and overriding it has little useful effect.
2311 Line spanners may have symbols at the beginning or end, which is
2312 contained in this sub-property. This is for internal use; it is
2313 recommended that @code{text} be used instead.
2316 This is a markup that is evaluated to yield the stencil. It is used
2317 to put @i{cresc.}, @i{tr} and other text on horizontal spanners.
2319 @lilypond[quote,ragged-right,fragment,relative=2,verbatim]
2320 \override TextSpanner #'(bound-details left text)
2321 = \markup { \small \bold Slower }
2322 c2\startTextSpan b c a\stopTextSpan
2325 @item stencil-align-dir-y
2326 @item stencil-offset
2327 Without setting one of these, the stencil is simply put at the
2328 end-point, centered on the line, as defined by the @code{X} and
2329 @code{Y} sub-properties. Setting either @code{stencil-align-dir-y}
2330 or @code{stencil-offset} will move the symbol at the edge vertically
2331 relative to the end point of the line:
2333 @lilypond[relative=1,fragment,verbatim]
2334 \override TextSpanner
2335 #'(bound-details left stencil-align-dir-y) = #-2
2336 \override TextSpanner
2337 #'(bound-details right stencil-align-dir-y) = #UP
2339 \override TextSpanner
2340 #'(bound-details left text) = #"ggg"
2341 \override TextSpanner
2342 #'(bound-details right text) = #"hhh"
2343 c4^\startTextSpan c c c \stopTextSpan
2346 Note that negative values move the text @emph{up}, contrary to the
2347 effect that might be expected, as a value of @code{-1} or
2348 @code{DOWN} means align the @emph{bottom} edge of the text with
2349 the spanner line. A value of @code{1} or @code{UP} aligns
2350 the top edge of the text with the spanner line.
2353 Setting this sub-property to @code{#t} produces an arrowhead at the
2357 This sub-property controls the space between the specified
2358 end point of the line and the actual end. Without padding, a
2359 glissando would start and end in the center of each note head.
2363 The music function @code{\endSpanners} terminates the spanner
2364 which starts on the immediately following note prematurely. It
2365 is terminated after exactly one note, or at the following bar line
2366 if @code{to-barline} is true and a bar line occurs before the next
2369 @lilypond[verbatim,quote,ragged-right,relative=2,fragment]
2371 c2 \startTextSpan c2 c2
2376 When using @code{\endSpanners} it is not necessary to close
2377 \startTextSpan with \stopTextSpan, nor is it necessary to close
2378 hairpins with @code{\!}.
2382 Internals Reference: @rinternals{TextSpanner},
2383 @rinternals{Glissando}, @rinternals{VoiceFollower},
2384 @rinternals{TrillSpanner},
2385 @rinternals{line-spanner-interface}.
2388 @node Visibility of objects
2389 @subsection Visibility of objects
2391 @cindex objects, visibility of
2392 @cindex grobs, visibility of
2393 @cindex visibility of objects
2395 There are four main ways in which the visibility of layout objects
2396 can be controlled: their stencil can be removed, they can be made
2397 transparent, they can be colored white, or their
2398 @code{break-visibility} property can be overridden. The first
2399 three apply to all layout objects; the last to just a few -- the
2400 @emph{breakable} objects. The Learning Manual introduces these
2401 four techniques, see @rlearning{Visibility and color of objects}.
2403 There are also a few other techniques which are specific to
2404 certain layout objects. These are covered under Special
2408 * Removing the stencil::
2409 * Making objects transparent::
2410 * Painting objects white::
2411 * Using break-visibility::
2412 * Special considerations::
2416 @node Removing the stencil
2417 @unnumberedsubsubsec Removing the stencil
2419 @cindex stencil, removing
2421 Every layout object has a stencil property. By default this is set
2422 to the specific function which draws that object. If this property
2423 is overridden to @code{#f} no function will be called and the object
2424 will not be drawn. The default action can be recovered with
2427 @lilypond[quote,verbatim,relative=1]
2429 \override Score.BarLine #'stencil = ##f
2431 \revert Score.BarLine #'stencil
2435 @node Making objects transparent
2436 @unnumberedsubsubsec Making objects transparent
2438 @cindex transparent, making objects
2440 Every layout object has a transparent property which by default is
2441 set to @code{#f}. If set to @code{#t} the object still occupies
2442 space but is made invisible.
2444 @lilypond[quote,verbatim,relative=2]
2446 \once \override NoteHead #'transparent = ##t
2450 @node Painting objects white
2451 @unnumberedsubsubsec Painting objects white
2453 @cindex objects, coloring
2454 @cindex coloring objects
2456 @cindex printing order
2457 @cindex overwriting objects
2458 @cindex objects, overwriting
2459 @cindex grobs, overwriting
2461 Every layout object has a color property which by default is set
2462 to @code{black}. If this is overridden to @code{white} the object
2463 will be indistinguishable from the white background. However,
2464 if the object crosses other objects the color of the crossing
2465 points will be determined by the order in which they are drawn,
2466 and this may leave a ghostly image of the white object, as shown
2469 @lilypond[quote,verbatim,relative=2]
2470 \override Staff.Clef #'color = #white
2474 This may be avoided by changing the order of printing the objects.
2475 All layout objects have a @code{layer} property which should be set
2476 to an integer. Objects with the lowest value of @code{layer} are
2477 drawn first, then objects with progressively higher values are drawn,
2478 so objects with higher values overwrite objects with lower values.
2479 By default most objects are assigned a @code{layer} value of
2480 @code{1}, although a few objects, including @code{StaffSymbol} and
2481 @code{BarLine}, are assigned a value of @code{0}. The order of
2482 printing objects with the same value of @code{layer} is indeterminate.
2484 In the example above the white clef, with a default @code{layer}
2485 value of @code{1}, is drawn after the staff lines (default
2486 @code{layer} value @code{0}), so overwriting them. To change this,
2487 the @code{Clef} object must be given in a lower value of
2488 @code{layer}, say @code{-1}, so that it is drawn earlier:
2490 @lilypond[quote,verbatim,relative=2]
2491 \override Staff.Clef #'color = #white
2492 \override Staff.Clef #'layer = #-1
2496 @node Using break-visibility
2497 @unnumberedsubsubsec Using break-visibility
2499 @c TODO Add making other objects breakable
2501 @cindex break-visibility
2503 Most layout objects are printed only once, but some like
2504 bar lines, clefs, time signatures and key signatures, may need
2505 to be printed twice when a line break occurs -- once at the end
2506 of the line and again at the start of the next line. Such
2507 objects are called @emph{breakable}, and have a property, the
2508 @code{break-visibility} property to control their visibility
2509 at the three positions in which they may appear -- at the
2510 start of a line, within a line if they are changed, and at the
2511 end of a line if a change takes place there.
2513 For example, the time signature
2514 by default will be printed at the start of the first line, but
2515 nowhere else unless it changes, when it will be printed at the
2516 point at which the change occurs. If this change occurs at the
2517 end of a line the new time signature will be printed at the start
2518 of the next line and a cautionary time signature will be printed
2519 at the end of the previous line as well.
2521 This behaviour is controlled by the @code{break-visibility}
2522 property, which is explained in
2523 @c Leave this ref on a newline - formats incorrectly otherwise -td
2524 @rlearning{Visibility and color of objects}. This property takes
2525 a vector of three booleans which, in order, determine whether the
2526 object is printed at the end of, within the body of, or at the
2527 beginning of a line. Or to be more precise, before a line break,
2528 where there is no line break, or after a line break.
2530 Alternatively, these eight combinations may be specified
2531 by pre-defined functions, defined in @file{scm/output-lib.scm},
2532 where the last three columns indicate whether the layout objects
2533 will be visible in the positions shown at the head of the columns:
2535 @multitable {@code{begin-of-line-invisible}} {@code{'#(#t #t #t)}} {yes} {yes} {yes}
2536 @headitem Function @tab Vector @tab Before @tab At no @tab After
2537 @headitem form @tab form @tab break @tab break @tab break
2539 @item @code{all-visible} @tab @code{'#(#t #t #t)} @tab yes @tab yes @tab yes
2540 @item @code{begin-of-line-visible} @tab @code{'#(#f #f #t)} @tab no @tab no @tab yes
2541 @item @code{center-visible} @tab @code{'#(#f #t #f)} @tab no @tab yes @tab no
2542 @item @code{end-of-line-visible} @tab @code{'#(#t #f #f)} @tab yes @tab no @tab no
2543 @item @code{begin-of-line-invisible} @tab @code{'#(#t #t #f)} @tab yes @tab yes @tab no
2544 @item @code{center-invisible} @tab @code{'#(#t #f #t)} @tab yes @tab no @tab yes
2545 @item @code{end-of-line-invisible} @tab @code{'#(#f #t #t)} @tab no @tab yes @tab yes
2546 @item @code{all-invisible} @tab @code{'#(#f #f #f)} @tab no @tab no @tab no
2549 The default settings of @code{break-visibility} depend on the
2550 layout object. The following table shows all the layout objects
2551 of interest which are affected by @code{break-visibility} and the
2552 default setting of this property:
2554 @multitable @columnfractions .3 .3 .4
2556 @headitem Layout object @tab Usual context @tab Default setting
2558 @c omit Ambitus as it appears not to be affected by break-visibility -td
2559 @c @item @code{Ambitus} @tab as specified @tab @code{begin-of-line-visible}
2560 @item @code{BarLine} @tab @code{Score} @tab calculated
2561 @item @code{BarNumber} @tab @code{Score} @tab @code{begin-of-line-visible}
2562 @c omit the following item until it can be explained -td
2563 @c @item @code{BreakAlignGroup} @tab @code{Score} @tab calculated
2564 @item @code{BreathingSign} @tab @code{Voice} @tab @code{begin-of-line-invisible}
2565 @item @code{Clef} @tab @code{Staff} @tab @code{begin-of-line-visible}
2566 @item @code{Custos} @tab @code{Staff} @tab @code{end-of-line-visible}
2567 @item @code{DoublePercentRepeat} @tab @code{Voice} @tab @code{begin-of-line-invisible}
2568 @c omit KeyCancellation until it can be explained -td
2569 @c @item @code{KeyCancellation} @tab ?? @tab @code{begin-of-line-invisible}
2570 @item @code{KeySignature} @tab @code{Staff} @tab @code{begin-of-line-visible}
2571 @c omit LeftEdge until it can be explained -td
2572 @c @item @code{LeftEdge} @tab @code{Score} @tab @code{center-invisible}
2573 @item @code{OctavateEight} @tab @code{Staff} @tab @code{begin-of-line-visible}
2574 @item @code{RehearsalMark} @tab @code{Score} @tab @code{end-of-line-invisible}
2575 @item @code{TimeSignature} @tab @code{Staff} @tab @code{all-visible}
2579 The example below shows the use of the vector form to control the
2580 visibility of barlines:
2582 @lilypond[quote,verbatim,relative=1,ragged-right]
2585 % Remove bar line at the end of the current line
2586 \once \override Score.BarLine #'break-visibility = #'#(#f #t #t)
2592 Although all three components of the vector used to override
2593 @code{break-visibility} must be present, not all of them are
2594 effective with every layout object, and some combinations may
2595 even give errors. The following limitations apply:
2598 @item Bar lines cannot be printed at start of line.
2599 @item A bar number cannot be printed at the start of the first
2600 line unless it is set to be different from 1.
2601 @item Clef -- see below
2602 @item Double percent repeats are either all printed or all
2603 suppressed. Use begin-of line-invisible to print and
2604 all-invisible to suppress.
2605 @item Key signature -- see below
2606 @item OctavateEight -- see below
2609 @node Special considerations
2610 @unnumberedsubsubsec Special considerations
2612 @strong{@emph{Visibility following explicit changes}}
2614 @cindex key signature, visibility following explicit change
2615 @cindex explicitKeySignatureVisibility
2616 @cindex clef, visibility following explicit change
2617 @cindex explicitClefVisibility
2619 The @code{break-visibility} property controls the visibility of
2620 key signatures and changes of clef only at the start of lines,
2621 i.e. after a break. It has no effect on the visibility of the
2622 key signature or clef following an explicit key change or an
2623 explicit clef change within or at the end of a line. In the
2624 following example the key signature following the explicit change
2625 to B-flat major is still visible, even though @code{all-invisible}
2628 @lilypond[quote,verbatim,relative=1,ragged-right]
2631 % Try to remove all key signatures
2632 \override Staff.KeySignature #'break-visibility = #all-invisible
2640 The visibility of such explicit key signature and clef changes is
2641 controlled by the @code{explicitKeySignatureVisibility} and
2642 @code{explicitClefVisibility} properties. These are the equivalent
2643 of the @code{break-visibility} property and both take a vector of
2644 three booleans or the predefined functions listed above, exactly like
2645 @code{break-visibility}. Both are properties of the Staff context,
2646 not the layout objects themselves, and so they are set using the
2647 @code{\set} command. Both are set by default to @code{all-visible}.
2648 These properties control only the visibility of key signatures and
2649 clefs resulting from explicit changes and do not affect key
2650 signatures and clefs at the beginning of lines;
2651 @code{break-visibility} must still be overridden in the appropriate
2652 object to remove these.
2654 @lilypond[quote,verbatim,relative=1,ragged-right]
2657 \set Staff.explicitKeySignatureVisibility = #all-invisible
2658 \override Staff.KeySignature #'break-visibility = #all-invisible
2665 @strong{@emph{Visibility of cautionary accidentals}}
2667 To remove the cautionary accidentals printed at an explicit key
2668 change, set the Staff context property @code{printKeyCancellation}
2671 @lilypond[quote,verbatim,relative=1,ragged-right]
2674 \set Staff.explicitKeySignatureVisibility = #all-invisible
2675 \set Staff.printKeyCancellation = ##f
2676 \override Staff.KeySignature #'break-visibility = #all-invisible
2683 With these overrides only the accidentals before the notes remain
2684 to indicate the change of key.
2686 @c TODO Add visibility of cautionary accidentals before notes
2688 @strong{@emph{Automatic bars}}
2690 @cindex automaticBars
2691 @cindex bar lines, suppressing
2693 As a special case, the printing of bar lines can also be turned off
2694 by setting the @code{automaticBars} property in the Score context.
2695 If set to @code{#f}, bar lines will not be printed automatically;
2696 they must be explicitly created with a @code{\bar} command. Unlike
2697 the @code{\cadenzaOn} predefined command, measures are still counted.
2698 Bar generation will resume according to that count if this property
2699 is later set to @code{#t}. When set to @code{#f}, line breaks can
2700 occur only at explicit @code{\bar} commands.
2704 @strong{@emph{Octavated clefs}}
2706 @cindex octavated clefs, visibility of
2707 @cindex visibility of octavated clefs
2708 @cindex clefs, visibility of octavation
2710 The small octavation symbol on octavated clefs is produced by the
2711 @code{OctavateEight} layout object. Its visibility is controlled
2712 independently from that of the @code{Clef} object, so it is
2713 necessary to apply any required @code{break-visibility} overrides
2714 to both the @code{Clef} and the @code{OctavateEight} layout objects
2715 to fully suppress such clef symbols at the start of each line.
2717 For explicit clef changes, the @code{explicitClefVisibility}
2718 property controls both the clef symbol and any octavation symbol
2724 @rlearning{Visibility and color of objects}
2728 @subsection Line styles
2730 Some performance indications, e.g., @i{rallentando} and
2731 @i{accelerando} and @i{trills} are written as text and are
2732 extended over many measures with lines, sometimes dotted or wavy.
2734 These all use the same routines as the glissando for drawing the
2735 texts and the lines, and tuning their behavior is therefore also
2736 done in the same way. It is done with a spanner, and the routine
2737 responsible for drawing the spanners is
2738 @code{ly:line-interface::print}. This routine determines the
2739 exact location of the two @i{span points} and draws a line
2740 between them, in the style requested.
2742 Here is an example showing the different line styles available,
2743 and how to tune them.
2745 @lilypond[relative=2,ragged-right,verbatim,fragment]
2747 \once \override Glissando #'style = #'dashed-line
2749 \override Glissando #'style = #'dotted-line
2751 \override Glissando #'style = #'zigzag
2753 \override Glissando #'style = #'trill
2757 The locations of the end-points of the spanner are computed
2758 on-the-fly for every graphic object, but it is possible to
2762 @lilypond[relative=2,ragged-right,verbatim,fragment]
2764 \once \override Glissando #'(bound-details right Y) = #-2
2768 The value for @code{Y} is set to @code{-2} for the right end
2769 point. The left side may be similarly adjusted by specifying
2770 @code{left} instead of @code{right}.
2772 If @code{Y} is not set, the value is computed from the vertical
2773 position of the left and right attachment points of the spanner.
2775 Other adjustments of spanners are possible, for details, see
2778 @node Rotating objects
2779 @subsection Rotating objects
2781 Both layout objects and elements of markup text can be rotated by
2782 any angle about any point, but the method of doing so differs.
2785 * Rotating layout objects::
2789 @node Rotating layout objects
2790 @unnumberedsubsubsec Rotating layout objects
2792 @cindex rotating objects
2793 @cindex objects, rotating
2795 All layout objects which support the @code{grob-interface} can be
2796 rotated by setting their @code{rotation} property. This takes a
2797 list of three items: the angle of rotation counter-clockwise,
2798 and the x and y coordinates of the point relative to the object's
2799 reference point about which the rotation is to be performed. The
2800 angle of rotation is specified in degrees and the coordinates in
2803 The angle of rotation and the coordinates of the rotation point must
2804 be determined by trial and error.
2806 @cindex hairpins, angled
2807 @cindex angled hairpins
2809 There are only a few situations where the rotation of layout
2810 objects is useful; the following example shows one situation where
2813 @lilypond[quote,verbatim,relative=1]
2815 \override Hairpin #'rotation = #'(20 -1 0)
2819 @node Rotating markup
2820 @unnumberedsubsubsec Rotating markup
2822 All markup text can be rotated to lie at any angle by prefixing it
2823 with the @code{\rotate} command. The command takes two arguments:
2824 the angle of rotation in degrees counter-clockwise and the text to
2825 be rotated. The extents of the text are not rotated: they take
2826 their values from the extremes of the x and y coordinates of the
2827 rotated text. In the following example the
2828 @code{outside-staff-priority} property for text is set to @code{#f}
2829 to disable the automatic collision avoidance, which would push some
2830 of the text too high.
2832 @lilypond[quote,verbatim,relative=1]
2833 \override TextScript #'outside-staff-priority = ##f
2834 g4^\markup { \rotate #30 "a G" }
2835 b^\markup { \rotate #30 "a B" }
2836 des^\markup { \rotate #30 "a D-Flat" }
2837 fis^\markup { \rotate #30 "an F-Sharp" }
2840 @node Advanced tweaks
2841 @section Advanced tweaks
2843 This section discusses various approaches to fine tuning the
2844 appearance of the printed score.
2847 * Aligning objects::
2848 * Vertical grouping of grobs::
2849 * Modifying stencils::
2850 * Modifying shapes::
2856 @rlearning{Tweaking output},
2857 @rlearning{Other sources of information}.
2860 @ref{Explaining the Internals Reference},
2861 @ref{Modifying properties},
2862 @ref{Interfaces for programmers}.
2865 @file{scm/@/define@/-grobs@/.scm}.
2868 @rlsr{Tweaks and overrides}.
2870 Internals Reference:
2871 @rinternals{All layout objects}.
2874 @node Aligning objects
2875 @subsection Aligning objects
2877 Graphical objects which support the @code{self-alignment-interface} and/or
2878 the @code{side-position-interface} can be
2879 aligned to a previously placed object in a variety of ways. For a list of these objects, see
2880 @rinternals{self-alignment-interface} and @rinternals{side-position-interface}.
2882 All graphical objects have a reference point, a horizontal extent and a
2883 vertical extent. The horizontal extent is a pair of numbers
2884 giving the displacements from the reference point of the left and
2885 right edges, displacements to the left being negative. The
2886 vertical extent is a pair of numbers giving the displacement from
2887 the reference point to the bottom and top edges, displacements down
2890 An object's position on a staff is given by the values of the
2891 @code{X-offset} and @code{Y-offset} properties. The value of
2892 @code{X-offset} gives the displacement from the x coordinate of
2893 the reference point of the parent object, and the value of
2894 @code{Y-offset} gives the displacement from the center line of the
2895 staff. The values of @code{X-offset} and
2896 @code{Y-offset} may be set directly or may be set to be calculated
2897 by procedures in order to achieve alignment with the parent object
2900 @warning{Many objects have special positioning considerations which
2901 cause any setting of @code{X-offset} or @code{Y-offset} to be
2902 ignored or modified, even though the object supports the
2903 @code{self-alignment-interface}.}
2905 For example, an accidental can be repositioned
2906 vertically by setting @code{Y-offset} but any changes to
2907 @code{X-offset} have no effect.
2909 Rehearsal marks may be aligned with
2910 breakable objects such as bar lines, clef symbols, time signature
2911 symbols and key signatures. There are special properties to be
2912 found in the @code{break-aligned-interface} for positioning rehearsal
2913 marks on such objects.
2916 * Setting @code{X-offset} and @code{Y-offset} directly::
2917 * Using the @code{side-position-interface}::
2918 * Using the @code{self-alignment-interface}::
2919 * Using the @code{break-alignable-interface}::
2922 @node Setting @code{X-offset} and @code{Y-offset} directly
2923 @unnumberedsubsubsec Setting @code{X-offset} and @code{Y-offset} directly
2925 Numerical values may be given to the @code{X-offset} and @code{Y-offset}
2926 properties of many objects. The following example shows three
2927 notes with the default fingering position and the positions with @code{X-offset}
2928 and @code{Y-offset} modified.
2930 @lilypond[verbatim,quote,relative=2]
2933 -\tweak #'X-offset #0
2934 -\tweak #'Y-offset #0
2937 -\tweak #'X-offset #-1
2938 -\tweak #'Y-offset #1
2944 @node Using the @code{side-position-interface}
2945 @unnumberedsubsubsec Using the @code{side-position-interface}
2947 An object which supports the @code{side-position-interface} can be
2948 placed next to its parent object so that
2949 the specified edges of the two objects touch. The object may be
2950 placed above, below, to the right or to the left of the parent.
2951 The parent cannot be specified; it is determined by the order of
2952 elements in the input stream. Most objects have the associated
2953 note head as their parent.
2955 The values of the @code{side-axis} and @code{direction} properties
2956 determine where the object is to be placed, as follows:
2958 @c TODO add an example of each to the table
2960 @multitable @columnfractions .3 .3 .3
2961 @headitem @code{side-axis} @tab @code{direction} @tab
2962 @headitem property @tab property @tab Placement
2964 @item @code{0} @tab @code{-1} @tab left
2965 @item @code{0} @tab @code{1} @tab right
2966 @item @code{1} @tab @code{-1} @tab below
2967 @item @code{1} @tab @code{1} @tab above
2971 When @code{side-axis} is @code{0}, @code{X-offset} should be set to
2972 the procedure @code{ly:side-position-interface::x-aligned-side}.
2973 This procedure will return the correct value of @code{X-offset} to
2974 place the object to the left or right side of the parent according
2975 to value of @code{direction}.
2977 When @code{side-axis} is @code{1}, @code{Y-offset} should be set to
2978 the procedure @code{ly:side-position-interface::y-aligned-side}.
2979 This procedure will return the correct value of @code{Y-offset} to
2980 place the object to the top or bottom of the parent according
2981 to value of @code{direction}.
2983 @c TODO Add examples
2985 @node Using the @code{self-alignment-interface}
2986 @unnumberedsubsubsec Using the @code{self-alignment-interface}
2988 @emph{Self-aligning objects horizontally}
2990 The horizontal alignment of an object which supports the
2991 @code{self-alignment-interface} is controlled by the value of
2992 the @code{self-alignment-X} property, provided the object's
2993 @code{X-offset} property is set to
2994 @code{ly:self-alignment-interface::x-aligned-on-self}.
2995 @code{self-alignment-X} may be given any
2996 real value, in units of half the total X extent of the
2997 object. Negative values move the object to the right, positive
2998 to the left. A value of @code{0} centers the object on the
2999 reference point of its parent, a value of @code{-1} aligns the
3000 left edge of the object on the reference point of its parent,
3001 and a value of @code{1} aligns the right edge of the object on the
3002 reference point of its parent. The symbols @code{LEFT},
3003 @code{CENTER} and @code{RIGHT} may be used instead of the values
3004 @code{-1, 0, 1} respectively.
3006 Normally the @code{\override} command would be used to modify the
3007 value of @code{self-alignment-X}, but the @code{\tweak} command
3008 can be used to separately align several annotations on a single
3011 @lilypond[quote,verbatim,relative=1]
3013 -\tweak #'self-alignment-X #-1
3015 -\tweak #'self-alignment-X #0
3017 -\tweak #'self-alignment-X #RIGHT
3019 -\tweak #'self-alignment-X #-2.5
3020 ^"aligned further to the right"
3023 @emph{Self-aligning objects vertically}
3025 Objects may be aligned vertically in an analogous way to aligning
3026 them horizontally if the @code{Y-offset} property is set to
3027 @code{ly:self-alignment-interface::y-aligned-on-self}. However,
3028 other mechanisms are often involved in vertical alignment: the
3029 value of @code{Y-offset} is just one variable taken into account.
3030 This may make adjusting the value of some objects tricky.
3031 The units are just half the vertical extent of the object, which
3032 is usually quite small, so quite large numbers may be required.
3033 A value of @code{-1} aligns the lower edge of the object with
3034 the reference point of the parent object, a value of @code{0}
3035 aligns the center of the object with the reference point of the
3036 parent, and a value of @code{1} aligns the top edge of the object
3037 with the reference point of the parent. The symbols @code{DOWN},
3038 @code{CENTER}, @code{UP} may be substituted for @code{-1, 0, 1}
3041 @emph{Self-aligning objects in both directions}
3043 By setting both @code{X-offset} and @code{Y-offset}, an object may
3044 be aligned in both directions simultaneously.
3046 The following example shows how to adjust a fingering mark so
3047 that it nestles close to the note head.
3049 @lilypond[quote,verbatim,relative=2]
3051 -\tweak #'self-alignment-X #0.5 % move horizontally left
3052 -\tweak #'Y-offset #ly:self-alignment-interface::y-aligned-on-self
3053 -\tweak #'self-alignment-Y #-1 % move vertically up
3058 @unnumberedsubsubsec Using the @code{aligned-on-parent} procedures
3060 @c Cannot document as they do not seem to operate consistently on all objects -td
3061 @c TODO investigate further
3063 The @code{aligned-on-parent} procedures are used in the same way
3064 as the @code{aligned-on-self} procedures, they difference being
3065 that they permit an object to be aligned with the @emph{edges} of
3066 the parent rather than the parent's reference point. The following
3067 example shows the difference:
3071 @lilypond[verbatim,quote]
3077 @unnumberedsubsubsec Using the @code{centered-on-parent} procedures
3079 @c Cannot document as they do not seem to operate consistently on all objects -td
3080 @c TODO investigate further
3084 @c TODO The align-interface, BassFigureAlignment and VerticalAlignment
3086 @node Using the @code{break-alignable-interface}
3087 @unnumberedsubsubsec Using the @code{break-alignable-interface}
3089 @cindex align to objects
3090 @cindex break-align-symbols
3092 Rehearsal marks and bar numbers may be aligned with notation
3093 objects other than bar lines. These objects include @code{ambitus},
3094 @code{breathing-sign}, @code{clef}, @code{custos}, @code{staff-bar},
3095 @code{left-edge}, @code{key-cancellation}, @code{key-signature}, and
3096 @code{time-signature}.
3098 By default, rehearsal marks and bar numbers will be horizontally
3099 centered above the object:
3101 @lilypond[verbatim,quote,relative=1]
3103 % the RehearsalMark will be centered above the Clef
3104 \override Score.RehearsalMark #'break-align-symbols = #'(clef)
3109 % the RehearsalMark will be centered above the TimeSignature
3110 \override Score.RehearsalMark #'break-align-symbols = #'(time-signature)
3118 A list of possible target alignment objects may be specified. If
3119 some of the objects are invisible at that point due to the setting
3120 of @code{break-visibility} or the explicit visibility settings for
3121 keys and clefs, the rehearsal mark or bar number is aligned to the
3122 first object in the list which is visible. If no objects in the
3123 list are visible the object is aligned to the bar line. If the bar
3124 line is invisible the object is aligned to the place where the bar
3127 @lilypond[verbatim,quote,relative=1]
3129 % the RehearsalMark will be centered above the Key Signature
3130 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature clef)
3135 % the RehearsalMark will be centered above the Clef
3136 \set Staff.explicitKeySignatureVisibility = #all-invisible
3137 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature clef)
3144 The alignment of the rehearsal mark relative to the notation object
3145 can be changed, as shown in the following example. In a score with
3146 multiple staves, this setting should be done for all the staves.
3148 @lilypond[verbatim,quote,relative=1]
3149 % The RehearsalMark will be centered above the KeySignature
3150 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature)
3156 % The RehearsalMark will be aligned with the left edge of the KeySignature
3157 \once \override Score.KeySignature #'break-align-anchor-alignment = #LEFT
3161 % The RehearsalMark will be aligned with the right edge of the KeySignature
3162 \once \override Score.KeySignature #'break-align-anchor-alignment = #RIGHT
3168 The rehearsal mark can also be offset to the right or left of the left edge
3169 by an arbitrary amount. The units are staff-spaces:
3171 @lilypond[verbatim,quote,relative=1]
3172 % The RehearsalMark will be aligned with the left edge of the KeySignature
3173 % and then shifted right by 3.5 staff-spaces
3174 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature)
3175 \once \override Score.KeySignature #'break-align-anchor = #3.5
3179 % The RehearsalMark will be aligned with the left edge of the KeySignature
3180 % and then shifted left by 2 staff-spaces
3181 \once \override Score.KeySignature #'break-align-anchor = #-2
3188 @node Vertical grouping of grobs
3189 @subsection Vertical grouping of grobs
3191 @c FIXME Expand this section
3193 The VerticalAlignment and VerticalAxisGroup grobs work together.
3194 VerticalAxisGroup groups together different grobs like Staff, Lyrics,
3195 etc. VerticalAlignment then vertically aligns the different grobs
3196 grouped together by VerticalAxisGroup. There is usually only one
3197 VerticalAlignment per score but every Staff, Lyrics, etc. has its own
3201 @node Modifying stencils
3202 @subsection Modifying stencils
3204 All layout objects have a @code{stencil} property which is part of
3205 the @code{grob-interface}. By default, this property is usually
3206 set to a function specific to the object that is tailor-made to
3207 render the symbol which represents it in the output. For example,
3208 the standard setting for the @code{stencil} property of the
3209 @code{MultiMeasureRest} object is @code{ly:multi-measure-rest::print}.
3211 The standard symbol for any object can be replaced by modifying the
3212 @code{stencil} property to reference a different, specially-written,
3213 procedure. This requires a high level of knowledge of the internal
3214 workings of LilyPond, but there is an easier way which can often
3215 produce adequate results.
3217 This is to set the @code{stencil} property to the procedure which
3218 prints text -- @code{ly:text-interface::print} -- and to add a
3219 @code{text} property to the object which is set to contain the
3220 markup text which produces the required symbol. Due to the
3221 flexibility of markup, much can be achieved -- see in particular
3222 @ref{Graphic notation inside markup}.
3224 The following example demonstrates this by changing the note head
3225 symbol to a cross within a circle.
3227 @lilypond[verbatim,quote]
3229 \once \override NoteHead #'stencil = #ly:text-interface::print
3230 \once \override NoteHead #'text = \markup {
3232 \halign #-0.7 \draw-circle #0.85 #0.2 ##f
3233 \musicglyph #"noteheads.s2cross"
3241 Any of the glyphs in the feta Font can be supplied to the
3242 @code{\musicglyph} markup command -- see @ref{The Feta font}.
3244 @c TODO Add inserting eps files or ref to later
3246 @c TODO Add inserting Postscript or ref to later
3251 @ref{Graphic notation inside markup},
3252 @ref{Formatting text},
3253 @ref{Text markup commands},
3254 @ref{The Feta font}.
3257 @node Modifying shapes
3258 @subsection Modifying shapes
3261 * Modifying ties and slurs::
3264 @node Modifying ties and slurs
3265 @unnumberedsubsubsec Modifying ties and slurs
3267 Ties, slurs and phrasing slurs are drawn as third-order Bézier
3268 curves. If the shape of the tie or slur which is calculated
3269 automatically is not optimum, the shape may be modified manually by
3270 explicitly specifying the four control points required to define
3271 a third-order Bézier curve.
3273 Third-order or cubic Bézier curves are defined by four control
3274 points. The first and fourth control points are precisely the
3275 starting and ending points of the curve. The intermediate two
3276 control points define the shape. Animations showing how the curve
3277 is drawn can be found on the web, but the following description
3278 may be helpful. The curve starts from the first control point
3279 heading directly towards the second, gradually bending over to
3280 head towards the third and continuing to bend over to head towards
3281 the fourth, arriving there travelling directly from the third
3282 control point. The curve is entirely contained in the
3283 quadrilateral defined by the four control points.
3285 Here is an example of a case where the tie is not optimum, and
3286 where @code{\tieDown} would not help.
3288 @lilypond[verbatim,quote,relative=1]
3292 { r4 <g c,> <g c,> <g c,> }
3296 One way of improving this tie is to manually modify its control
3299 The coordinates of the Bézier control points are specified in units
3300 of staff-spaces. The X@tie{}coordinate is relative to the reference
3301 point of the note to which the tie or slur is attached, and the
3302 Y@tie{}coordinate is relative to the staff center line. The
3303 coordinates are entered as a list of four pairs of decimal numbers
3304 (reals). One approach is to estimate the coordinates of the two
3305 end points, and then guess the two intermediate points. The optimum
3306 values are then found by trial and error.
3308 It is useful to remember that a symmetric curve requires symmetric
3309 control points, and that Bézier curves have the useful property that
3310 transformations of the curve such as translation, rotation and
3311 scaling can be achieved by applying the same transformation to the
3312 curve's control points.
3314 For the example above the following override gives a satisfactory
3317 @lilypond[verbatim,quote,relative=1]
3320 #'control-points = #'((1 . -1) (3 . 0.6) (12.5 . 0.6) (14.5 . -1))
3323 { r4 <g c,> <g c,> <g c,>4 }
3329 It is not possible to modify shapes of ties or slurs by changing
3330 the @code{control-points} property if there are more than one at
3331 the same musical moment, not even by using the @code{\tweak}