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 }
448 \new Voice = "A" { s1*5 } % Keep Voice "A" alive for 5 bars
449 \new Voice = "B" { s1*5 } % Keep Voice "B" alive for 5 bars
454 \context Voice = "A" {
458 \context Voice = "B" {
462 \context Voice = "A" { \musicA }
463 \context Voice = "B" { \musicB }
464 \context Voice = "A" { \musicA }
475 @cindex lyrics, aligning with sporadic melody
477 The following example shows how a sporadic melody line with lyrics
478 might be written using this approach. In a real situation the
479 melody and accompaniment would consist of several different
482 @lilypond[quote,verbatim]
483 melody = \relative c'' { a4 a a a }
484 accompaniment = \relative c' { d4 d d d }
485 words = \lyricmode { These words fol -- low the mel -- o -- dy }
488 \new Staff = "music" {
490 \new Voice = "melody" {
492 s1*4 % Keep Voice "melody" alive for 4 bars
495 \new Voice = "accompaniment" {
500 \context Voice = "melody" { \melody }
501 \context Voice = "accompaniment" { \accompaniment }
503 \context Voice = "accompaniment" { \accompaniment }
505 \context Voice = "melody" { \melody }
506 \context Voice = "accompaniment" { \accompaniment }
511 \new Lyrics \with { alignAboveContext = #"music" }
512 \lyricsto "melody" { \words }
517 An alternative way, which may be better in many circumstances, is
518 to keep the melody line alive by simply including spacer notes to
519 line it up correctly with the accompaniment:
521 @lilypond[quote,verbatim]
522 melody = \relative c'' {
528 accompaniment = \relative c' {
534 words = \lyricmode { These words fol -- low the mel -- o -- dy }
538 \new Staff = "music" {
540 \new Voice = "melody" {
544 \new Voice = "accompaniment" {
550 \new Lyrics \with { alignAboveContext = #"music" }
551 \lyricsto "melody" { \words }
557 @node Modifying context plug-ins
558 @subsection Modifying context plug-ins
560 @c TODO Should this be Modifying engravers or Modifying contexts?
562 Notation contexts (like @code{Score} and @code{Staff}) not only
564 they also contain plug-ins called @q{engravers} that create notation
565 elements. For example, the @code{Voice} context contains a
566 @code{Note_head_engraver} and the @code{Staff} context contains a
567 @code{Key_signature_engraver}.
569 For a full a description of each plug-in, see
571 @rinternals{Engravers and Performers}.
574 Internals Reference @expansion{} Translation @expansion{} Engravers.
576 Every context described in
578 @rinternals{Contexts}
581 Internals Reference @expansion{} Translation @expansion{} Context.
583 lists the engravers used for that context.
586 It can be useful to shuffle around these plug-ins. This is done by
587 starting a new context with @code{\new} or @code{\context}, and
593 \new @var{context} \with @{
606 where the @dots{} should be the name of an engraver. Here is a simple
607 example which removes @code{Time_signature_engraver} and
608 @code{Clef_engraver} from a @code{Staff} context,
610 @lilypond[quote,relative=1,verbatim,fragment]
616 \remove "Time_signature_engraver"
617 \remove "Clef_engraver"
624 In the second staff there are no time signature or clef symbols. This
625 is a rather crude method of making objects disappear since it will affect
626 the entire staff. This method also influences the spacing, which may or
627 may not be desirable. More sophisticated methods of blanking objects
628 are shown in @rlearning{Visibility and color of objects}.
630 The next example shows a practical application. Bar lines and time
631 signatures are normally synchronized across the score. This is done
632 by the @code{Timing_translator} and @code{Default_bar_line_engraver}.
633 This plug-in keeps an administration of time signature, location
634 within the measure, etc. By moving these engraver from @code{Score} to
635 @code{Staff} context, we can have a score where each staff has its own
638 @cindex polymetric scores
639 @cindex Time signatures, multiple
641 @lilypond[quote,relative=1,ragged-right,verbatim,fragment]
643 \remove "Timing_translator"
644 \remove "Default_bar_line_engraver"
647 \consists "Timing_translator"
648 \consists "Default_bar_line_engraver"
654 \consists "Timing_translator"
655 \consists "Default_bar_line_engraver"
665 Usually the order in which the engravers are specified
666 does not matter, but in a few special cases the order
667 is important, for example where one engraver writes
668 a property and another reads it, or where one engraver
669 creates a grob and another must process it. The order in
670 which the engravers are specified is the order in which
671 they are called to carry out their processing.
673 The following orderings are important: the
674 @code{Bar_engraver} must normally be first, and
675 the @code{New_fingering_engraver} must come before
676 the @code{Script_column_engraver}. There may be others
677 with ordering dependencies.
679 @node Changing context default settings
680 @subsection Changing context default settings
682 The context settings which are to be used by default in
683 @code{Score}, @code{Staff} and @code{Voice} contexts may be specified
684 in a @code{\layout} block, as illustrated in the following example.
685 The @code{\layout} block should be placed within the @code{\score}
686 block to which it is to apply, but outside any music.
688 Note that the @code{\set} command itself and the context must be
689 omitted when the context default values are specified in this way:
691 @lilypond[quote,verbatim]
694 a4^"Really small, thicker stems, no time signature" a a a
701 \override Stem #'thickness = #4.0
702 \remove "Time_signature_engraver"
708 In this example, the @code{\Staff} command specifies that the
709 subsequent specifications are to be applied to all staves within
712 Modifications can be made to the @code{Score} context or all
713 @code{Voice} contexts in a similar way.
717 It is not possible to collect context changes in a variable and apply
718 them to a @code{\context} definition by referring to that variable.
720 The @code{\RemoveEmptyStaffContext} will overwrite your current
721 @code{\Staff} settings. If you wish to change the defaults for a
722 staff which uses @code{\RemoveEmptyStaffContext}, you must do so
723 after calling @code{\RemoveEmptyStaffContext}, ie
728 \RemoveEmptyStaffContext
730 \override Stem #'thickness = #4.0
735 @c TODO: add \with in here.
739 @node Defining new contexts
740 @subsection Defining new contexts
742 Specific contexts, like @code{Staff} and @code{Voice}, are made of
743 simple building blocks. It is possible to create new types of
744 contexts with different combinations of engraver plug-ins.
746 The next example shows how to build a different type of
747 @code{Voice} context from scratch. It will be similar to
748 @code{Voice}, but only prints centered slash note heads. It can be used
749 to indicate improvisation in jazz pieces,
751 @lilypond[quote,ragged-right]
754 \type "Engraver_group"
755 \consists "Note_heads_engraver"
756 \consists "Rhythmic_column_engraver"
757 \consists "Text_engraver"
758 \consists Pitch_squash_engraver
759 squashedPosition = #0
760 \override NoteHead #'style = #'slash
761 \override Stem #'transparent = ##t
765 \accepts "ImproVoice"
769 a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
770 c4 c^"undress" c_"while playing :)" c }
776 These settings are defined within a @code{\context} block inside a
777 @code{\layout} block,
787 In the following discussion, the example input shown should go in place
788 of the @dots{} in the previous fragment.
790 First it is necessary to define a name for the new context:
796 Since it is similar to the @code{Voice}, we want commands that work
797 on (existing) @code{Voice}s to remain working. This is achieved by
798 giving the new context an alias @code{Voice},
804 The context will print notes and instructive texts, so we need to add
805 the engravers which provide this functionality,
808 \consists Note_heads_engraver
809 \consists Text_engraver
812 but we only need this on the center line,
815 \consists Pitch_squash_engraver
816 squashedPosition = #0
819 The @rinternals{Pitch_squash_engraver} modifies note heads (created
820 by @rinternals{Note_heads_engraver}) and sets their vertical
821 position to the value of @code{squashedPosition}, in this case@tie{}@code{0},
824 The notes look like a slash, and have no stem,
827 \override NoteHead #'style = #'slash
828 \override Stem #'transparent = ##t
831 All these plug-ins have to cooperate, and this is achieved with a
832 special plug-in, which must be marked with the keyword @code{\type}.
833 This should always be @code{Engraver_group}.
836 \type "Engraver_group"
844 \type "Engraver_group"
845 \consists "Note_heads_engraver"
846 \consists "Text_engraver"
847 \consists Pitch_squash_engraver
848 squashedPosition = #0
849 \override NoteHead #'style = #'slash
850 \override Stem #'transparent = ##t
856 Contexts form hierarchies. We want to hang the @code{ImproVoice}
857 under @code{Staff}, just like normal @code{Voice}s. Therefore, we
858 modify the @code{Staff} definition with the @code{\accepts}
869 The opposite of @code{\accepts} is @code{\denies},
870 which is sometimes needed when reusing existing context definitions.
872 Putting both into a @code{\layout} block, like
882 \accepts "ImproVoice"
887 Then the output at the start of this subsection can be entered as
895 c c_"while playing :)"
902 @node Aligning contexts
903 @subsection Aligning contexts
905 New contexts may be aligned above or below existing contexts. This
906 could be useful in setting up a vocal staff (@rlearning{Vocal ensembles}) and
909 @c TODO Better example needed. Ref LM, and expand on it.
912 @funindex alignAboveContext
913 @funindex alignBelowContext
915 @lilypond[quote,ragged-right]
918 \relative c' \new Staff = "main" {
921 \new Staff \with { alignAboveContext = #"main" } \ossia
928 @cindex nested contexts
929 @cindex contexts, nested
934 Contexts like @code{PianoStaff} can contain other contexts
935 nested within them. Contexts which are acceptable for nesting
936 are defined by the @qq{accepts} list of a context. Contexts
937 which are not in this list are placed below the outer context
938 in the printed score.
939 For example, the @code{PianoStaff} context is defined by default
940 to accept @code{Staff} and @code{FiguredBass} contexts within
941 it, but not (for example) a @code{Lyrics} context. So in the
942 following structure the lyrics are placed below the piano staff
943 rather than between the two staves:
945 @lilypond[verbatim,quote,relative=1]
948 \new Staff { e4 d c2 }
949 \addlyrics { Three blind mice }
957 The @qq{accepts} list of a context can be modified to include
958 additional nested contexts, so if we wanted the lyrics to appear
959 between the two staves we could use:
961 @lilypond[verbatim,quote,relative=1]
962 \new PianoStaff \with { \accepts Lyrics }
964 \new Staff { e4 d c2 }
965 \addlyrics { Three blind mice }
973 The opposite of @code{\accepts} is @code{\denies}; this removes a
974 context from the @qq{accepts} list.
976 @node Explaining the Internals Reference
977 @section Explaining the Internals Reference
981 * Navigating the program reference::
982 * Layout interfaces::
983 * Determining the grob property::
984 * Naming conventions::
987 @node Navigating the program reference
988 @subsection Navigating the program reference
990 @c TODO remove this (it's in the LM)
991 @c Replace with more factual directions
993 Suppose we want to move the fingering indication in the fragment
996 @lilypond[quote,fragment,relative=2,verbatim]
1002 If you visit the documentation on fingering instructions (in
1003 @ref{Fingering instructions}), you will notice:
1008 Internals Reference: @rinternals{Fingering}.
1013 @c outdated info; probably will delete.
1015 This fragment points to two parts of the program reference: a page
1016 on @code{FingeringEvent} and one on @code{Fingering}.
1018 The page on @code{FingeringEvent} describes the properties of the music
1019 expression for the input @code{-2}. The page contains many links
1020 forward. For example, it says
1023 Accepted by: @rinternals{Fingering_engraver},
1027 That link brings us to the documentation for the Engraver, the
1031 This engraver creates the following layout objects: @rinternals{Fingering}.
1034 In other words, once the @code{FingeringEvent}s are interpreted, the
1035 @code{Fingering_engraver} plug-in will process them.
1039 @c I can't figure out what this is supposed to mean. -gp
1041 The @code{Fingering_engraver} is also listed to create
1042 @rinternals{Fingering} objects,
1044 @c old info? it doesn't make any sense to me with our current docs.
1046 second bit of information listed under @b{See also} in the Notation
1051 The programmer's reference is available as an HTML document. It is
1052 highly recommended that you read it in HTML form, either online or
1053 by downloading the HTML documentation. This section will be much more
1054 difficult to understand if you are using the
1058 Follow the link to @rinternals{Fingering}. At the top of the
1062 Fingering objects are created by: @rinternals{Fingering_engraver} and
1063 @rinternals{New_fingering_engraver}.
1066 By following related links inside the program reference, we can follow the
1067 flow of information within the program:
1071 @item @rinternals{Fingering}:
1072 @rinternals{Fingering} objects are created by:
1073 @rinternals{Fingering_engraver}
1075 @item @rinternals{Fingering_engraver}:
1076 Music types accepted: @rinternals{fingering-event}
1078 @item @rinternals{fingering-event}:
1079 Music event type @code{fingering-event} is in Music expressions named
1080 @rinternals{FingeringEvent}
1083 This path goes against the flow of information in the program: it
1084 starts from the output, and ends at the input event. You could
1085 also start at an input event, and read with the flow of
1086 information, eventually ending up at the output object(s).
1088 The program reference can also be browsed like a normal document. It
1089 contains chapters on
1091 @rinternals{Music definitions},
1094 @code{Music definitions}
1096 on @rinternals{Translation}, and the @rinternals{Backend}. Every
1097 chapter lists all the definitions used and all properties that may be
1101 @node Layout interfaces
1102 @subsection Layout interfaces
1104 @cindex interface, layout
1105 @cindex layout interface
1108 The HTML page that we found in the previous section describes the
1109 layout object called @rinternals{Fingering}. Such an object is a
1110 symbol within the score. It has properties that store numbers (like
1111 thicknesses and directions), but also pointers to related objects. A
1112 layout object is also called a @emph{Grob}, which is short for Graphical
1113 Object. For more details about Grobs, see @rinternals{grob-interface}.
1115 The page for @code{Fingering} lists the definitions for the
1116 @code{Fingering} object. For example, the page says
1119 @code{padding} (dimension, in staff space):
1125 which means that the number will be kept at a distance of at least 0.5
1129 Each layout object may have several functions as a notational or
1130 typographical element. For example, the Fingering object
1131 has the following aspects
1135 Its size is independent of the horizontal spacing, unlike slurs or beams.
1138 It is a piece of text. Granted, it is usually a very short text.
1141 That piece of text is typeset with a font, unlike slurs or beams.
1144 Horizontally, the center of the symbol should be aligned to the
1145 center of the note head.
1148 Vertically, the symbol is placed next to the note and the staff.
1151 The vertical position is also coordinated with other superscript
1152 and subscript symbols.
1155 Each of these aspects is captured in so-called @emph{interface}s,
1156 which are listed on the @rinternals{Fingering} page at the bottom
1159 This object supports the following interfaces:
1160 @rinternals{item-interface},
1161 @rinternals{self-alignment-interface},
1162 @rinternals{side-position-interface}, @rinternals{text-interface},
1163 @rinternals{text-script-interface}, @rinternals{font-interface},
1164 @rinternals{finger-interface}, and @rinternals{grob-interface}.
1167 Clicking any of the links will take you to the page of the respective
1168 object interface. Each interface has a number of properties. Some of
1169 them are not user-serviceable (@q{Internal properties}), but others
1172 We have been talking of @emph{the} @code{Fingering} object, but actually it
1173 does not amount to much. The initialization file (see
1174 @rlearning{Other sources of information})
1175 @file{scm/@/define@/-grobs@/.scm} shows the soul of the @q{object},
1180 (avoid-slur . around)
1181 (slur-padding . 0.2)
1182 (staff-padding . 0.5)
1183 (self-alignment-X . 0)
1184 (self-alignment-Y . 0)
1185 (script-priority . 100)
1186 (stencil . ,ly:text-interface::print)
1187 (direction . ,ly:script-interface::calc-direction)
1188 (font-encoding . fetaNumber)
1189 (font-size . -5) ; don't overlap when next to heads.
1190 (meta . ((class . Item)
1191 (interfaces . (finger-interface
1193 text-script-interface
1195 side-position-interface
1196 self-alignment-interface
1197 item-interface))))))
1201 As you can see, the @code{Fingering} object is nothing more than a
1202 bunch of variable settings, and the webpage in the Internals Reference
1203 is directly generated from this definition.
1206 @node Determining the grob property
1207 @subsection Determining the grob property
1209 @c TODO remove this (it's in the LM)
1210 @c Replace with more factual directions
1212 Recall that we wanted to change the position of the @b{2} in
1214 @lilypond[quote,fragment,relative=2,verbatim]
1220 Since the @b{2} is vertically positioned next to its note, we have to
1221 meddle with the interface associated with this positioning. This is
1222 done using @code{side-position-interface}. The page for this interface
1226 @code{side-position-interface}
1228 Position a victim object (this one) next to other objects (the
1229 support). The property @code{direction} signifies where to put the
1230 victim object relative to the support (left or right, up or down?)
1235 Below this description, the variable @code{padding} is described as
1240 (dimension, in staff space)
1242 Add this much extra space between objects that are next to each other.
1246 By increasing the value of @code{padding}, we can move the
1247 fingering away from the note head. The following command inserts
1248 3 staff spaces of white
1249 between the note and the fingering:
1251 \once \override Voice.Fingering #'padding = #3
1254 Inserting this command before the Fingering object is created,
1255 i.e., before @code{c2}, yields the following result:
1257 @lilypond[quote,relative=2,fragment,verbatim]
1258 \once \override Voice.Fingering #'padding = #3
1265 In this case, the context for this tweak is @code{Voice}. This
1266 fact can also be deduced from the program reference, for the page for
1267 the @rinternals{Fingering_engraver} plug-in says
1270 Fingering_engraver is part of contexts: @dots{} @rinternals{Voice}
1274 @node Naming conventions
1275 @subsection Naming conventions
1277 Another thing that is needed, is an overview of the various naming
1280 scheme functions: lowercase-with-hyphens (incl. one-word
1282 scheme functions: ly:plus-scheme-style
1283 music events, music classes and music properties:
1285 Grob interfaces: scheme-style
1286 backend properties: scheme-style (but X and Y!)
1287 contexts (and MusicExpressions and grobs): Capitalized or
1289 context properties: lowercaseFollowedByCamelCase
1291 Capitalized_followed_by_lowercase_and_with_underscores
1293 Which of these are conventions and which are rules?
1294 Which are rules of the underlying language, and which are
1298 @node Modifying properties
1299 @section Modifying properties
1301 @c TODO change the menu and subsection node names to use
1302 @c backslash once the new macro to handle the refs
1303 @c is available. Need to find and change all refs at
1304 @c the same time. -td
1307 * Overview of modifying properties::
1309 * The override command::
1310 * The tweak command::
1311 * set versus override::
1315 @node Overview of modifying properties
1316 @subsection Overview of modifying properties
1318 Each context is responsible for creating certain types of graphical
1319 objects. The settings used for printing these objects are also stored by
1320 context. By changing these settings, the appearance of objects can be
1323 The syntax for this is
1326 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1329 Here @var{name} is the name of a graphical object, like
1330 @code{Stem} or @code{NoteHead}, and @var{property} is an internal
1331 variable of the formatting system (@q{grob property} or @q{layout
1332 property}). The latter is a symbol, so it must be quoted. The
1333 subsection @ref{Modifying properties}, explains what to fill in
1334 for @var{name}, @var{property}, and @var{value}. Here we only
1335 discuss the functionality of this command.
1340 \override Staff.Stem #'thickness = #4.0
1344 makes stems thicker (the default is 1.3, with staff line thickness as a
1345 unit). Since the command specifies @code{Staff} as context, it only
1346 applies to the current staff. Other staves will keep their normal
1347 appearance. Here we see the command in action:
1349 @lilypond[quote,verbatim,relative=2,fragment]
1351 \override Staff.Stem #'thickness = #4.0
1357 The @code{\override} command changes the definition of the @code{Stem}
1358 within the current @code{Staff}. After the command is interpreted
1359 all stems are thickened.
1361 Analogous to @code{\set}, the @var{context} argument may be left out,
1362 causing the default context @code{Voice} to be used. Adding
1363 @code{\once} applies the change during one timestep only.
1365 @lilypond[quote,fragment,verbatim,relative=2]
1367 \once \override Stem #'thickness = #4.0
1372 The @code{\override} must be done before the object is
1373 started. Therefore, when altering @emph{Spanner} objects such as slurs
1374 or beams, the @code{\override} command must be executed at the moment
1375 when the object is created. In this example,
1377 @lilypond[quote,fragment,verbatim,relative=2]
1378 \override Slur #'thickness = #3.0
1380 \override Beam #'thickness = #0.6
1385 the slur is fatter but the beam is not. This is because the command for
1386 @code{Beam} comes after the Beam is started, so it has no effect.
1388 Analogous to @code{\unset}, the @code{\revert} command for a context
1389 undoes an @code{\override} command; like with @code{\unset}, it only
1390 affects settings that were made in the same context. In other words, the
1391 @code{\revert} in the next example does not do anything.
1394 \override Voice.Stem #'thickness = #4.0
1395 \revert Staff.Stem #'thickness
1398 Some tweakable options are called @q{subproperties} and reside inside
1399 properties. To tweak those, use commands of the form
1401 @c leave this as a long long
1403 \override @var{context}.@var{name} #'@var{property} #'@var{subproperty} = #@var{value}
1410 \override Stem #'(details beamed-lengths) = #'(4 4 3)
1415 Internals: @rinternals{OverrideProperty}, @rinternals{RevertProperty},
1416 @rinternals{PropertySet}, @rinternals{Backend}, and
1417 @rinternals{All layout objects}.
1422 The back-end is not very strict in type-checking object properties.
1423 Cyclic references in Scheme values for properties can cause hangs
1424 or crashes, or both.
1428 @node The set command
1429 @subsection The @code{\set} command
1433 @cindex changing properties
1435 Each context can have different @emph{properties}, variables contained
1436 in that context. They can be changed during the interpretation step.
1437 This is achieved by inserting the @code{\set} command in the music,
1440 \set @var{context}.@var{prop} = #@var{value}
1444 @lilypond[quote,verbatim,relative=2,fragment]
1446 \set Score.skipBars = ##t
1450 This command skips measures that have no notes. The result is that
1451 multi-rests are condensed. The value assigned is a Scheme object. In
1452 this case, it is @code{#t}, the boolean True value.
1454 If the @var{context} argument is left out, then the current bottom-most
1455 context (typically @code{ChordNames}, @code{Voice}, or
1456 @code{Lyrics}) is used. In this example,
1458 @lilypond[quote,verbatim,relative=2,fragment]
1460 \set autoBeaming = ##f
1465 the @var{context} argument to @code{\set} is left out, so automatic
1466 beaming is switched off in the current @rinternals{Voice}. Note that
1467 the bottom-most context does not always contain the property that you
1468 wish to change -- for example, attempting to set the @code{skipBars}
1469 property (of the bottom-most context, in this case @code{Voice}) will
1472 @lilypond[quote,verbatim,relative=2,fragment]
1478 Contexts are hierarchical, so if a bigger context was specified, for
1479 example @code{Staff}, then the change would also apply to all
1480 @code{Voice}s in the current stave. The change is applied
1481 @q{on-the-fly}, during the music, so that the setting only affects the
1482 second group of eighth notes.
1486 There is also an @code{\unset} command,
1488 \unset @var{context}.@var{prop}
1492 which removes the definition of @var{prop}. This command removes
1493 the definition only if it is set in @var{context}, so
1496 \set Staff.autoBeaming = ##f
1500 introduces a property setting at @code{Staff} level. The setting also
1501 applies to the current @code{Voice}. However,
1504 \unset Voice.autoBeaming
1508 does not have any effect. To cancel this setting, the @code{\unset}
1509 must be specified on the same level as the original @code{\set}. In
1510 other words, undoing the effect of @code{Staff.autoBeaming = ##f}
1513 \unset Staff.autoBeaming
1516 Like @code{\set}, the @var{context} argument does not have to be
1517 specified for a bottom context, so the two statements
1520 \set Voice.autoBeaming = ##t
1521 \set autoBeaming = ##t
1529 Settings that should only apply to a single time-step can be entered
1530 with @code{\once}, for example in
1532 @lilypond[quote,verbatim,relative=2,fragment]
1534 \once \set fontSize = #4.7
1539 the property @code{fontSize} is unset automatically after the second
1542 A full description of all available context properties is in the
1543 program reference, see
1545 @rinternals{Tunable context properties}.
1548 Translation @expansion{} Tunable context properties.
1553 @node The override command
1554 @subsection The @code{\override} command
1556 Commands which change output generally look like
1559 \override Voice.Stem #'thickness = #3.0
1563 To construct this tweak we must determine these bits of information:
1566 @item the context: here @code{Voice}.
1567 @item the layout object: here @code{Stem}.
1568 @item the layout property: here @code{thickness}.
1569 @item a sensible value: here @code{3.0}.
1572 Some tweakable options are called @q{subproperties} and reside inside
1573 properties. To tweak those, use commands in the form
1576 \override Stem #'(details beamed-lengths) = #'(4 4 3)
1579 @cindex internal documentation
1580 @cindex finding graphical objects
1581 @cindex graphical object descriptions
1584 @cindex internal documentation
1586 For many properties, regardless of the data type of the property, setting the
1587 property to false ( @code{##f} ) will result in turning it off, causing
1588 LilyPond to ignore that property entirely. This is particularly useful for
1589 turning off grob properties which may otherwise be causing problems.
1591 We demonstrate how to glean this information from the notation manual
1592 and the program reference.
1595 @node The tweak command
1596 @subsection The @code{\tweak} command
1601 In some cases, it is possible to take a short-cut for tuning
1602 graphical objects. For objects that are created directly from
1603 an item in the input file, you can use the @code{\tweak} command.
1606 @lilypond[relative=2,verbatim]
1611 \tweak #'duration-log #1
1614 -\tweak #'padding #8
1618 @cindex chord, modifying one note in
1620 But the main use of the @code{\tweak} command is to modify just
1621 one of a number of notation elements which start at the same musical
1622 moment, like the notes of a chord, or tuplet brackets which start
1625 For an introduction to the syntax and uses of the tweak command
1626 see @rlearning{Tweaking methods}.
1628 The @code{\tweak} command sets a property in the following object
1629 directly, without requiring the grob name or context to be
1630 specified. For this to work, it is necessary for the @code{\tweak}
1631 command to remain immediately adjacent to the object to which it is
1632 to apply after the input file has been converted to a music stream.
1633 This is often not the case, as many additional elements are inserted
1634 into the music stream implicitly. For example, when a note which is
1635 not part of a chord is processed, LilyPond implicitly inserts a
1636 @code{ChordEvent} event before the note, so separating the tweak
1637 from the note. However, if chord symbols are placed round the
1638 tweak and the note, the @code{\tweak} command comes after the
1639 @code{ChordEvent} in the music stream, so remaining adjacent to the
1640 note, and able to modify it.
1644 @lilypond[relative=2,verbatim,quote]
1645 <\tweak #'color #red c>4
1651 @lilypond[relative=2,verbatim,quote]
1652 \tweak #'color #red c4
1655 When several similar items are placed at the same musical moment,
1656 the @code{\override} command cannot be used to modify just one of
1657 them -- this is where the @code{\tweak} command must be used.
1658 Items which may appear more than once at the same musical moment
1659 include the following:
1661 @c TODO expand to include any further uses of \tweak
1663 @item note heads of notes inside a chord
1664 @item articulation signs on a single note
1665 @item ties between notes in a chord
1666 @item tuplet brackets starting at the same time
1669 @c TODO add examples of these
1672 and @code{\tweak} may be used to modify any single occurrence of
1675 Notably the @code{\tweak} command cannot be used to modify stems,
1676 beams or accidentals directly, since these are generated later by
1677 note heads, rather than by music elements in the input stream.
1678 Nor can a @code{\tweak} command be used to modify clefs or time
1679 signatures, since these become separated from any preceding
1680 @code{\tweak} command in the input stream by the automatic
1681 insertion of extra elements required to specify the context.
1683 But the @code{\tweak} command can be used as an alternative to
1684 the @code{\override} command to modify those notational elements
1685 that do not cause any additional implicit elements to be added
1686 before them in the music stream. For example, slurs may be
1687 modified in this way:
1689 @lilypond[verbatim,quote,relative=1]
1690 c-\tweak #'thickness #5 ( d e f)
1693 Also several @code{\tweak} commands may be placed before a
1694 notational element -- all affect it:
1696 @lilypond[verbatim,quote,relative=1]
1698 -\tweak #'style #'dashed-line
1699 -\tweak #'dash-fraction #0.2
1700 -\tweak #'thickness #3
1701 -\tweak #'color #red
1706 The music stream which is generated from a section of an input file,
1707 including any automatically inserted elements, may be examined,
1708 see @ref{Displaying music expressions}. This may be helpful in
1709 determining what may be modified by a @code{\tweak} command.
1714 @rlearning{Tweaking methods}.
1717 @ref{Displaying music expressions}.
1722 @cindex tweaks in a variable
1723 The @code{\tweak} command cannot be used inside a variable.
1725 @cindex tweaks in lyrics
1726 The @code{\tweak} commands cannot be used in @code{\lyricmode}.
1728 @cindex tweaking control points
1729 @cindex control points, tweaking
1731 The @code{\tweak} command cannot be used to modify the control
1732 points of just one of several ties in a chord, other than the first
1733 one encountered in the input file.
1735 @node set versus override
1736 @subsection @code{\set} vs. @code{\override}
1738 We have seen two methods of changing properties: @code{\set} and
1739 @code{\override}. There are actually two different kinds of
1742 Contexts can have properties, which are usually named in
1743 @code{studlyCaps}. They mostly control the translation from
1744 music to notation, eg. @code{localKeySignature} (for determining
1745 whether to print accidentals), @code{measurePosition} (for
1746 determining when to print a bar line). Context properties can
1747 change value over time while interpreting a piece of music;
1748 @code{measurePosition} is an obvious example of
1749 this. Context properties are modified with @code{\set}.
1751 There is a special type of context property: the element
1752 description. These properties are named in @code{StudlyCaps}
1753 (starting with capital letters). They contain the
1754 @q{default settings} for said graphical object as an
1755 association list. See @file{scm/@/define@/-grobs@/.scm}
1756 to see what kind of settings there are. Element descriptions
1757 may be modified with @code{\override}.
1759 @code{\override} is actually a shorthand;
1762 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1766 is more or less equivalent to
1768 @c leave this long line -gp
1770 \set @var{context}.@var{name} #'@var{property} = #(cons (cons '@var{property} @var{value}) <previous value of @var{context})
1773 The value of @code{context} (the alist) is used to initialize
1774 the properties of individual grobs. Grobs also have
1775 properties, named in Scheme style, with
1776 @code{dashed-words}. The values of grob properties change
1777 during the formatting process: formatting basically amounts
1778 to computing properties using callback functions.
1780 @code{fontSize} is a special property: it is equivalent to
1781 entering @code{\override ... #'font-size} for all pertinent
1782 objects. Since this is a common change, the special
1783 property (modified with @code{\set}) was created.
1786 @node Useful concepts and properties
1787 @section Useful concepts and properties
1792 * Direction and placement::
1793 * Distances and measurements::
1794 * Staff symbol properties::
1796 * Visibility of objects::
1798 * Rotating objects::
1802 @subsection Input modes
1804 The way in which the notation contained within an input file is
1805 interpreted is determined by the current input mode.
1809 This is activated with the @code{\chordmode} command, and causes
1810 input to be interpreted with the syntax of chord notation, see
1811 @ref{Chord notation}. Chords are rendered as notes on a staff.
1813 Chord mode is also activated with the @code{\chords} command.
1814 This also creates a new @code{ChordNames} context and
1815 causes the following input to be interpreted with the syntax of
1816 chord notation and rendered as chord names in the @code{ChordNames}
1817 context, see @ref{Printing chord names}.
1821 This is activated with the @code{\drummode} command, and causes
1822 input to be interpreted with the syntax of drum notation, see
1823 @ref{Basic percussion notation}.
1825 Drum mode is also activated with the @code{\drums} command.
1826 This also creates a new @code{DrumStaff} context and causes the
1827 following input to be interpreted with the syntax of drum notation
1828 and rendered as drum symbols on a drum staff, see @ref{Basic
1829 percussion notation}.
1831 @strong{Figure mode}
1833 This is activated with the @code{\figuremode} command, and causes
1834 input to be interpreted with the syntax of figured bass, see
1835 @ref{Entering figured bass}.
1837 Figure mode is also activated with the @code{\figures} command.
1838 This also creates a new @code{FiguredBass} context and causes the
1839 following input to be interpreted with the figured bass syntax
1840 and rendered as figured bass symbols in the @code{FiguredBass}
1841 context, see @ref{Introduction to figured bass}.
1843 @strong{Fret and tab modes}
1845 There are no special input modes for entering fret and tab symbols.
1847 To create tab diagrams, enter notes or chords in note mode and
1848 render them in a @code{TabStaff} context, see
1849 @ref{Default tablatures}.
1851 To create fret diagrams above a staff, you have two choices.
1852 You can either use the @code{FretBoards} context (see
1853 @ref{Automatic fret diagrams} or you can enter them as a markup
1854 above the notes using the @code{\fret-diagram} command (see
1855 @ref{Fret diagram markups}).
1857 @strong{Lyrics mode}
1859 This is activated with the @code{\lyricmode} command, and causes
1860 input to be interpreted as lyric syllables with optional durations
1861 and associated lyric modifiers, see @ref{Vocal music}.
1863 Lyric mode is also activated with the @code{\addlyrics} command.
1864 This also creates a new @code{Lyrics} context and an implicit
1865 @code{\lyricsto} command which associates the following lyrics
1866 with the preceding music.
1868 @strong{Markup mode}
1870 This is activated with the @code{\markup} command, and causes
1871 input to be interpreted with the syntax of markup, see
1872 @ref{Text markup commands}.
1874 @c silly work-around for texinfo broken-ness
1875 @c (@strong{Note...} causes a spurious cross-reference in Info)
1878 This is the default mode or it may be activated with the
1879 @code{\notemode} command. Input is interpreted as pitches,
1880 durations, markup, etc and typeset as musical notation on a staff.
1882 It is not normally necessary to specify note mode explicitly, but
1883 it may be useful to do so in certain situations, for example if you
1884 are in lyric mode, chord mode or any other mode and want to insert
1885 something that only can be done with note mode syntax.
1887 For example, to indicate dynamic markings for the verses of a
1888 choral pieces it is necessary to enter note mode to interpret
1891 @lilypond[verbatim,relative=2,quote]
1894 \notemode{\set stanza = \markup{ \dynamic f 1. } }
1898 \notemode{\set stanza = \markup{ \dynamic p 2. } }
1905 @node Direction and placement
1906 @subsection Direction and placement
1908 In typesetting music the direction and placement of many items is
1909 a matter of choice. For example, the stems of notes can
1910 be directed up or down; lyrics, dynamics, and other expressive
1911 marks may be placed above or below the staff; text may be aligned
1912 left, right or center; etc. Most of these choices may be left to
1913 be determined automatically by LilyPond, but in some cases it may
1914 be desirable to force a particular direction or placement.
1916 @strong{Default actions}
1918 By default some directions are always up or always down (e.g.
1919 dynamics or fermata), while other things can alternate between
1920 up or down based on the stem direction (like slurs or accents).
1922 @c TODO Add table showing these
1924 @strong{Context layout order}
1926 Contexts are normally positioned in a system from top to bottom
1927 in the order in which they are encountered. Note, however, that
1928 a context will be created implicitly if a command is encountered
1929 when there is no suitable context available to contain it. When
1930 contexts are nested, the outer context will exclude inner contexts
1931 which are not included in its @qq{accepts} list; excluded contexts
1932 will be repositioned below the outer context.
1934 The default order in which contexts are laid out and the
1935 @qq{accepts} list can be changed, see @ref{Aligning contexts}.
1937 @strong{Articulation direction indicators}
1939 When adding articulations to notes the direction indicator,
1940 @code{^} (meaning @qq{up}), @code{_} (meaning @qq{down}) or
1941 @code{-} (meaning @qq{use default direction}), can usually be
1942 omitted, in which case @code{-} is assumed. But a direction
1943 indicator is @strong{always} required before
1946 @item @code{\tweak} commands
1947 @item @code{\markup} commands
1948 @item @code{\tag} commands
1949 @item string markups, e.g. -"string"
1950 @item fingering instructions, e.g. @code{-1}
1951 @item articulation shortcuts, e.g. @code{-.}, @code{->}, @code{--}
1954 These indications affect only the next note.
1956 @lilypond[verbatim,quote,relative=2]
1963 @strong{The direction property}
1965 The position or direction of many layout objects is controlled
1966 by the @code{direction} property.
1968 The value of the @code{direction} property may be
1969 set to @code{1}, meaning @qq{up} or @qq{above}, or to @code{-1},
1970 meaning @qq{down} or @qq{below}. The symbols @code{UP} and
1971 @code{DOWN} may be used instead of @code{1} and @code{-1}
1972 respectively. The default direction may be specified by setting
1973 @code{direction} to @code{0} or @code{CENTER}. Alternatively,
1974 in many cases predefined commands
1975 exist to specify the direction. These are all of the form
1978 @code{\xxxUp}, @code{xxxDown}, @code{xxxNeutral}
1981 where @code{xxxNeutral} means @qq{use the default direction}.
1982 See @rlearning{Within-staff objects}.
1984 In a few cases, arpeggio being the only common example, the value
1985 of the @code{direction} property specifies whether the object
1986 is to be placed to the right or left of the parent object. In
1987 this case @code{-1} or @code{LEFT} means @qq{to the left} and
1988 @code{1} or @code{RIGHT} means @qq{to the right}. @code{0}
1989 or @code{CENTER} means @qq{use the default} direction, as before.
1992 These all have side-axis set to #X
1993 AmbitusAccidental - direction has no effect
1995 StanzaNumber - not tried
1996 TrillPitchAccidental - not tried
1997 TrillPitchGroup - not tried
2000 These indications affect all notes until they are cancelled.
2002 @lilypond[verbatim,quote,relative=2]
2013 @node Distances and measurements
2014 @subsection Distances and measurements
2016 @cindex distances, absolute
2017 @cindex distances, scaled
2024 Distances in LilyPond are of two types: absolute and scaled.
2026 Absolute distances are used for specifying margins, indents, and
2027 other page layout details, and are by default specified in
2028 millimeters. Distances may be specified in other units by
2029 following the quantity by @code{\mm}, @code{\cm},
2030 @code{\in}@tie{}(inches), or @code{\pt}@tie{}(points, 1/72.27
2031 of an inch). Page layout distances can also be specified in
2032 scalable units (see the following paragraph) by appending
2033 @code{\staff-space} to the quantity.
2034 Page layout is described in detail in @ref{Page formatting}.
2036 Scaled distances are always specified in units of the staff-space
2037 or, rarely, the half staff-space. The staff-space is the distance
2038 between two adjacent staff lines. The default value can be changed
2039 globally by setting the global staff size, or it can be overridden
2040 locally by changing the @code{staff-space} property of
2041 @code{StaffSymbol}. Scaled distances automatically scale with any
2042 change to the either the global staff size or the
2043 @code{staff-space} property of @code{StaffSymbol}, but fonts scale
2044 automatically only with changes to the global staff size.
2045 The global staff size thus enables the overall size of a rendered
2046 score to be easily varied. For the methods of setting the global
2047 staff size see @ref{Setting the staff size}.
2051 If just a section of a score needs to be rendered to a different
2052 scale, for example an ossia section or a footnote, the global staff
2053 size cannot simply be changed as this would affect the entire score.
2054 In such cases the change in size is made by overriding both the
2055 @code{staff-space} property of @code{StaffSymbol} and the size of
2056 the fonts. A Scheme function, @code{magstep}, is available to
2057 convert from a font size change to the equivalent change in
2058 @code{staff-space}. For an explanation and an example of its use,
2059 see @rlearning{Length and thickness of objects}.
2064 @rlearning{Length and thickness of objects}.
2067 @ref{Page formatting},
2068 @ref{Setting the staff size}.
2071 @node Staff symbol properties
2072 @subsection Staff symbol properties
2074 @cindex adjusting staff symbol
2075 @cindex drawing staff symbol
2076 @cindex staff symbol, setting of
2078 @c TODO Extend or remove this section. See also NR 1.6.2 Staff symbol
2079 @c Need to think of uses for these properties. Eg 'line-positions
2080 @c is used in a snippet to thicken centre line.
2081 @c If retained, add @ref to here in 1.6.2 -td
2083 The vertical position of staff lines and the number of staff lines
2084 can be defined at the same time. As the following example shows,
2085 note positions are not influenced by the staff line positions.
2087 @warning{The @code{'line-positions} property overrides the
2088 @code{'line-count} property. The number of staff lines is
2089 implicitly defined by the number of elements in the list of values
2090 for @code{'line-positions}.}
2092 @lilypond[verbatim,quote,relative=1]
2094 \override StaffSymbol #'line-positions = #'(7 3 0 -4 -6 -7)
2099 The width of a staff can be modified. The units are staff
2100 spaces. The spacing of objects inside the staff is not affected by
2103 @lilypond[verbatim,quote,relative=1]
2105 \override StaffSymbol #'width = #23
2112 @subsection Spanners
2114 Many objects of musical notation extend over several notes or even
2115 several bars. Examples are slurs, beams, tuplet brackets, volta
2116 repeat brackets, crescendi, trills, and glissandi. Such objects
2117 are collectively called @qq{spanners}, and have special properties to control
2118 their appearance and behaviour. Some of these properties are common
2119 to all spanners; others are restricted to a sub-set of the spanners.
2121 All spanners support the @code{spanner-interface}. A few, esentially
2122 those that draw a straight line between the two objects, support in
2123 addition the @code{line-spanner-interface}.
2125 @unnumberedsubsubsec Using the @code{spanner-interface}
2127 This interface provides two properties that apply to several spanners.
2129 @strong{@i{The @code{minimum-length} property}}
2131 The minimum length of the spanner is specified by the
2132 @code{minimum-length} property. Increasing this usually has the
2133 necessary effect of increasing the spacing of the notes between the
2134 two end points. However, this override has no effect on
2135 many spanners, as their length is determined by other considerations.
2136 A few examples where it is effective are shown below.
2146 Works as long as callback is made:
2150 Works not at all for:
2159 @lilypond[verbatim,quote,relative=2]
2162 % increase the length of the tie
2163 -\tweak #'minimum-length #5
2167 @lilypond[verbatim,quote,relative=2]
2169 \compressFullBarRests
2171 % increase the length of the rest bar
2172 \once \override MultiMeasureRest #'minimum-length = #20
2177 @lilypond[verbatim,quote,relative=2]
2179 % increase the length of the hairpin
2180 \override Hairpin #'minimum-length = #20
2184 This override can also be used to increase the length of slurs and
2187 @lilypond[verbatim,quote,relative=2]
2190 -\tweak #'minimum-length #5
2195 -\tweak #'minimum-length #5
2199 For some layout objects, the @code{minimum-length} property becomes
2200 effective only if the @code{set-spacing-rods} procedure is called
2201 explicitly. To do this, the @code{springs-and-rods} property should
2202 be set to @code{ly:spanner::set-spacing-rods}. For example,
2203 the minimum length of a glissando has no effect unless the
2204 @code{springs-and-rods} property is set:
2206 @lilypond[verbatim,quote,relative=1]
2210 % not effective alone
2211 \once \override Glissando #'minimum-length = #20
2214 % effective only when both overrides are present
2215 \once \override Glissando #'minimum-length = #20
2216 \once \override Glissando #'springs-and-rods = #ly:spanner::set-spacing-rods
2220 The same is true of the @code{Beam} object:
2222 @lilypond[verbatim,quote,relative=1]
2223 % not effective alone
2224 \once \override Beam #'minimum-length = #20
2227 % effective only when both overrides are present
2228 \once \override Beam #'minimum-length = #20
2229 \once \override Beam #'springs-and-rods = #ly:spanner::set-spacing-rods
2233 @strong{@i{The @code{to-barline} property}}
2235 The second useful property of the @code{spanner-interface} is
2236 @code{to-barline}. By default this is true, causing hairpins and
2237 other spanners which are terminated on the first note of a measure to
2238 end instead on the immediately preceding bar line. If set to false,
2239 the spanner will extend beyond the bar line and end on the note
2242 @lilypond[verbatim,quote,relative=2]
2243 a \< a a a a \! a a a \break
2244 \override Hairpin #'to-barline = ##f
2245 a \< a a a a \! a a a
2248 This property is not effective for all spanners. For example,
2249 seting it to @code{#t} has no effect on slurs or phrasing slurs
2250 or on other spanners for which terminating on the bar line would
2253 @unnumberedsubsubsec Using the @code{line-spanner-interface}
2255 Objects which support the @code{line-spanner-interface} include
2258 @item @code{DynamicTextSpanner}
2259 @item @code{Glissando}
2260 @item @code{TextSpanner}
2261 @item @code{TrillSpanner}
2262 @item @code{VoiceFollower}
2265 The routine responsible for drawing the stencils for these spanners is
2266 @code{ly:line-interface::print}. This routine determines the
2267 exact location of the two end points and draws a line
2268 between them, in the style requested. The locations of the two
2269 end points of the spanner are computed on-the-fly, but it is
2270 possible to override their Y-coordinates. The
2271 properties which need to be specified are nested
2272 two levels down within the property hierarchy, but the syntax of
2273 the @code{\override} command is quite simple:
2275 @lilypond[relative=2,quote,verbatim]
2277 \once \override Glissando #'(bound-details left Y) = #3
2278 \once \override Glissando #'(bound-details right Y) = #-2
2282 The units for the @code{Y} property are @code{staff-space}s,
2283 with the center line of the staff being the zero point.
2284 For the glissando, this is the value for @code{Y} at the
2285 X-coordinate corresponding to the center point of each note head,
2286 if the line is imagined to be extended to there.
2288 If @code{Y} is not set, the value is computed from the vertical
2289 position of the corresponding attachment point of the spanner.
2291 In case of a line break, the values for the end points are
2292 specified by the @code{left-broken} and @code{right-broken}
2293 sub-lists of @code{bound-details}. For example:
2295 @lilypond[relative=2,ragged-right,verbatim,fragment]
2296 \override Glissando #'breakable = ##t
2297 \override Glissando #'(bound-details right-broken Y) = #-3
2298 c1 \glissando \break
2303 A number of further properties of the @code{left} and
2304 @code{right} sub-lists of the @code{bound-details} property
2305 may be modified in the same way as @code{Y}:
2309 This sets the Y-coordinate of the end point, in @code{staff-space}s
2310 offset from the staff center line. By default, it is the center of
2311 the bound object, so a glissando points to the vertical center of
2314 For horizontal spanners, such as text spanners and trill spanners,
2315 it is hardcoded to 0.
2318 This determines where the line starts and ends in the X-direction,
2319 relative to the bound object. So, a value of @code{-1} (or
2320 @code{LEFT}) makes the line start/end at the left side of the note
2321 head it is attached to.
2324 This is the absolute X-coordinate of the end point. It is usually
2325 computed on the fly, and overriding it has little useful effect.
2328 Line spanners may have symbols at the beginning or end, which is
2329 contained in this sub-property. This is for internal use; it is
2330 recommended that @code{text} be used instead.
2333 This is a markup that is evaluated to yield the stencil. It is used
2334 to put @i{cresc.}, @i{tr} and other text on horizontal spanners.
2336 @lilypond[quote,ragged-right,fragment,relative=2,verbatim]
2337 \override TextSpanner #'(bound-details left text)
2338 = \markup { \small \bold Slower }
2339 c2\startTextSpan b c a\stopTextSpan
2342 @item stencil-align-dir-y
2343 @item stencil-offset
2344 Without setting one of these, the stencil is simply put at the
2345 end-point, centered on the line, as defined by the @code{X} and
2346 @code{Y} sub-properties. Setting either @code{stencil-align-dir-y}
2347 or @code{stencil-offset} will move the symbol at the edge vertically
2348 relative to the end point of the line:
2350 @lilypond[relative=1,fragment,verbatim]
2351 \override TextSpanner
2352 #'(bound-details left stencil-align-dir-y) = #-2
2353 \override TextSpanner
2354 #'(bound-details right stencil-align-dir-y) = #UP
2356 \override TextSpanner
2357 #'(bound-details left text) = #"ggg"
2358 \override TextSpanner
2359 #'(bound-details right text) = #"hhh"
2360 c4^\startTextSpan c c c \stopTextSpan
2363 Note that negative values move the text @emph{up}, contrary to the
2364 effect that might be expected, as a value of @code{-1} or
2365 @code{DOWN} means align the @emph{bottom} edge of the text with
2366 the spanner line. A value of @code{1} or @code{UP} aligns
2367 the top edge of the text with the spanner line.
2370 Setting this sub-property to @code{#t} produces an arrowhead at the
2374 This sub-property controls the space between the specified
2375 end point of the line and the actual end. Without padding, a
2376 glissando would start and end in the center of each note head.
2380 The music function @code{\endSpanners} terminates the spanner
2381 which starts on the immediately following note prematurely. It
2382 is terminated after exactly one note, or at the following bar line
2383 if @code{to-barline} is true and a bar line occurs before the next
2386 @lilypond[verbatim,quote,ragged-right,relative=2,fragment]
2388 c2 \startTextSpan c2 c2
2393 When using @code{\endSpanners} it is not necessary to close
2394 \startTextSpan with \stopTextSpan, nor is it necessary to close
2395 hairpins with @code{\!}.
2399 Internals Reference: @rinternals{TextSpanner},
2400 @rinternals{Glissando}, @rinternals{VoiceFollower},
2401 @rinternals{TrillSpanner},
2402 @rinternals{line-spanner-interface}.
2405 @node Visibility of objects
2406 @subsection Visibility of objects
2408 @cindex objects, visibility of
2409 @cindex grobs, visibility of
2410 @cindex visibility of objects
2412 There are four main ways in which the visibility of layout objects
2413 can be controlled: their stencil can be removed, they can be made
2414 transparent, they can be colored white, or their
2415 @code{break-visibility} property can be overridden. The first
2416 three apply to all layout objects; the last to just a few -- the
2417 @emph{breakable} objects. The Learning Manual introduces these
2418 four techniques, see @rlearning{Visibility and color of objects}.
2420 There are also a few other techniques which are specific to
2421 certain layout objects. These are covered under Special
2425 * Removing the stencil::
2426 * Making objects transparent::
2427 * Painting objects white::
2428 * Using break-visibility::
2429 * Special considerations::
2433 @node Removing the stencil
2434 @unnumberedsubsubsec Removing the stencil
2436 @cindex stencil, removing
2438 Every layout object has a stencil property. By default this is set
2439 to the specific function which draws that object. If this property
2440 is overridden to @code{#f} no function will be called and the object
2441 will not be drawn. The default action can be recovered with
2444 @lilypond[quote,verbatim,relative=1]
2446 \override Score.BarLine #'stencil = ##f
2448 \revert Score.BarLine #'stencil
2452 @node Making objects transparent
2453 @unnumberedsubsubsec Making objects transparent
2455 @cindex transparent, making objects
2457 Every layout object has a transparent property which by default is
2458 set to @code{#f}. If set to @code{#t} the object still occupies
2459 space but is made invisible.
2461 @lilypond[quote,verbatim,relative=2]
2463 \once \override NoteHead #'transparent = ##t
2467 @node Painting objects white
2468 @unnumberedsubsubsec Painting objects white
2470 @cindex objects, coloring
2471 @cindex coloring objects
2473 @cindex printing order
2474 @cindex overwriting objects
2475 @cindex objects, overwriting
2476 @cindex grobs, overwriting
2478 Every layout object has a color property which by default is set
2479 to @code{black}. If this is overridden to @code{white} the object
2480 will be indistinguishable from the white background. However,
2481 if the object crosses other objects the color of the crossing
2482 points will be determined by the order in which they are drawn,
2483 and this may leave a ghostly image of the white object, as shown
2486 @lilypond[quote,verbatim,relative=2]
2487 \override Staff.Clef #'color = #white
2491 This may be avoided by changing the order of printing the objects.
2492 All layout objects have a @code{layer} property which should be set
2493 to an integer. Objects with the lowest value of @code{layer} are
2494 drawn first, then objects with progressively higher values are drawn,
2495 so objects with higher values overwrite objects with lower values.
2496 By default most objects are assigned a @code{layer} value of
2497 @code{1}, although a few objects, including @code{StaffSymbol} and
2498 @code{BarLine}, are assigned a value of @code{0}. The order of
2499 printing objects with the same value of @code{layer} is indeterminate.
2501 In the example above the white clef, with a default @code{layer}
2502 value of @code{1}, is drawn after the staff lines (default
2503 @code{layer} value @code{0}), so overwriting them. To change this,
2504 the @code{Clef} object must be given in a lower value of
2505 @code{layer}, say @code{-1}, so that it is drawn earlier:
2507 @lilypond[quote,verbatim,relative=2]
2508 \override Staff.Clef #'color = #white
2509 \override Staff.Clef #'layer = #-1
2513 @node Using break-visibility
2514 @unnumberedsubsubsec Using break-visibility
2516 @c TODO Add making other objects breakable
2518 @cindex break-visibility
2520 Most layout objects are printed only once, but some like
2521 bar lines, clefs, time signatures and key signatures, may need
2522 to be printed twice when a line break occurs -- once at the end
2523 of the line and again at the start of the next line. Such
2524 objects are called @emph{breakable}, and have a property, the
2525 @code{break-visibility} property to control their visibility
2526 at the three positions in which they may appear -- at the
2527 start of a line, within a line if they are changed, and at the
2528 end of a line if a change takes place there.
2530 For example, the time signature
2531 by default will be printed at the start of the first line, but
2532 nowhere else unless it changes, when it will be printed at the
2533 point at which the change occurs. If this change occurs at the
2534 end of a line the new time signature will be printed at the start
2535 of the next line and a cautionary time signature will be printed
2536 at the end of the previous line as well.
2538 This behaviour is controlled by the @code{break-visibility}
2539 property, which is explained in
2540 @c Leave this ref on a newline - formats incorrectly otherwise -td
2541 @rlearning{Visibility and color of objects}. This property takes
2542 a vector of three booleans which, in order, determine whether the
2543 object is printed at the end of, within the body of, or at the
2544 beginning of a line. Or to be more precise, before a line break,
2545 where there is no line break, or after a line break.
2547 Alternatively, these eight combinations may be specified
2548 by pre-defined functions, defined in @file{scm/output-lib.scm},
2549 where the last three columns indicate whether the layout objects
2550 will be visible in the positions shown at the head of the columns:
2552 @multitable {@code{begin-of-line-invisible}} {@code{'#(#t #t #t)}} {yes} {yes} {yes}
2553 @headitem Function @tab Vector @tab Before @tab At no @tab After
2554 @headitem form @tab form @tab break @tab break @tab break
2556 @item @code{all-visible} @tab @code{'#(#t #t #t)} @tab yes @tab yes @tab yes
2557 @item @code{begin-of-line-visible} @tab @code{'#(#f #f #t)} @tab no @tab no @tab yes
2558 @item @code{center-visible} @tab @code{'#(#f #t #f)} @tab no @tab yes @tab no
2559 @item @code{end-of-line-visible} @tab @code{'#(#t #f #f)} @tab yes @tab no @tab no
2560 @item @code{begin-of-line-invisible} @tab @code{'#(#t #t #f)} @tab yes @tab yes @tab no
2561 @item @code{center-invisible} @tab @code{'#(#t #f #t)} @tab yes @tab no @tab yes
2562 @item @code{end-of-line-invisible} @tab @code{'#(#f #t #t)} @tab no @tab yes @tab yes
2563 @item @code{all-invisible} @tab @code{'#(#f #f #f)} @tab no @tab no @tab no
2566 The default settings of @code{break-visibility} depend on the
2567 layout object. The following table shows all the layout objects
2568 of interest which are affected by @code{break-visibility} and the
2569 default setting of this property:
2571 @multitable @columnfractions .3 .3 .4
2573 @headitem Layout object @tab Usual context @tab Default setting
2575 @c omit Ambitus as it appears not to be affected by break-visibility -td
2576 @c @item @code{Ambitus} @tab as specified @tab @code{begin-of-line-visible}
2577 @item @code{BarLine} @tab @code{Score} @tab calculated
2578 @item @code{BarNumber} @tab @code{Score} @tab @code{begin-of-line-visible}
2579 @c omit the following item until it can be explained -td
2580 @c @item @code{BreakAlignGroup} @tab @code{Score} @tab calculated
2581 @item @code{BreathingSign} @tab @code{Voice} @tab @code{begin-of-line-invisible}
2582 @item @code{Clef} @tab @code{Staff} @tab @code{begin-of-line-visible}
2583 @item @code{Custos} @tab @code{Staff} @tab @code{end-of-line-visible}
2584 @item @code{DoublePercentRepeat} @tab @code{Voice} @tab @code{begin-of-line-invisible}
2585 @c omit KeyCancellation until it can be explained -td
2586 @c @item @code{KeyCancellation} @tab ?? @tab @code{begin-of-line-invisible}
2587 @item @code{KeySignature} @tab @code{Staff} @tab @code{begin-of-line-visible}
2588 @c omit LeftEdge until it can be explained -td
2589 @c @item @code{LeftEdge} @tab @code{Score} @tab @code{center-invisible}
2590 @item @code{OctavateEight} @tab @code{Staff} @tab @code{begin-of-line-visible}
2591 @item @code{RehearsalMark} @tab @code{Score} @tab @code{end-of-line-invisible}
2592 @item @code{TimeSignature} @tab @code{Staff} @tab @code{all-visible}
2596 The example below shows the use of the vector form to control the
2597 visibility of barlines:
2599 @lilypond[quote,verbatim,relative=1,ragged-right]
2602 % Remove bar line at the end of the current line
2603 \once \override Score.BarLine #'break-visibility = #'#(#f #t #t)
2609 Although all three components of the vector used to override
2610 @code{break-visibility} must be present, not all of them are
2611 effective with every layout object, and some combinations may
2612 even give errors. The following limitations apply:
2615 @item Bar lines cannot be printed at start of line.
2616 @item A bar number cannot be printed at the start of the first
2617 line unless it is set to be different from 1.
2618 @item Clef -- see below
2619 @item Double percent repeats are either all printed or all
2620 suppressed. Use begin-of line-invisible to print and
2621 all-invisible to suppress.
2622 @item Key signature -- see below
2623 @item OctavateEight -- see below
2626 @node Special considerations
2627 @unnumberedsubsubsec Special considerations
2629 @strong{@emph{Visibility following explicit changes}}
2631 @cindex key signature, visibility following explicit change
2632 @cindex explicitKeySignatureVisibility
2633 @cindex clef, visibility following explicit change
2634 @cindex explicitClefVisibility
2636 The @code{break-visibility} property controls the visibility of
2637 key signatures and changes of clef only at the start of lines,
2638 i.e. after a break. It has no effect on the visibility of the
2639 key signature or clef following an explicit key change or an
2640 explicit clef change within or at the end of a line. In the
2641 following example the key signature following the explicit change
2642 to B-flat major is still visible, even though @code{all-invisible}
2645 @lilypond[quote,verbatim,relative=1,ragged-right]
2648 % Try to remove all key signatures
2649 \override Staff.KeySignature #'break-visibility = #all-invisible
2657 The visibility of such explicit key signature and clef changes is
2658 controlled by the @code{explicitKeySignatureVisibility} and
2659 @code{explicitClefVisibility} properties. These are the equivalent
2660 of the @code{break-visibility} property and both take a vector of
2661 three booleans or the predefined functions listed above, exactly like
2662 @code{break-visibility}. Both are properties of the Staff context,
2663 not the layout objects themselves, and so they are set using the
2664 @code{\set} command. Both are set by default to @code{all-visible}.
2665 These properties control only the visibility of key signatures and
2666 clefs resulting from explicit changes and do not affect key
2667 signatures and clefs at the beginning of lines;
2668 @code{break-visibility} must still be overridden in the appropriate
2669 object to remove these.
2671 @lilypond[quote,verbatim,relative=1,ragged-right]
2674 \set Staff.explicitKeySignatureVisibility = #all-invisible
2675 \override Staff.KeySignature #'break-visibility = #all-invisible
2682 @strong{@emph{Visibility of cautionary accidentals}}
2684 To remove the cautionary accidentals printed at an explicit key
2685 change, set the Staff context property @code{printKeyCancellation}
2688 @lilypond[quote,verbatim,relative=1,ragged-right]
2691 \set Staff.explicitKeySignatureVisibility = #all-invisible
2692 \set Staff.printKeyCancellation = ##f
2693 \override Staff.KeySignature #'break-visibility = #all-invisible
2700 With these overrides only the accidentals before the notes remain
2701 to indicate the change of key.
2703 @c TODO Add visibility of cautionary accidentals before notes
2705 @strong{@emph{Automatic bars}}
2707 @cindex automaticBars
2708 @cindex bar lines, suppressing
2710 As a special case, the printing of bar lines can also be turned off
2711 by setting the @code{automaticBars} property in the Score context.
2712 If set to @code{#f}, bar lines will not be printed automatically;
2713 they must be explicitly created with a @code{\bar} command. Unlike
2714 the @code{\cadenzaOn} predefined command, measures are still counted.
2715 Bar generation will resume according to that count if this property
2716 is later set to @code{#t}. When set to @code{#f}, line breaks can
2717 occur only at explicit @code{\bar} commands.
2721 @strong{@emph{Octavated clefs}}
2723 @cindex octavated clefs, visibility of
2724 @cindex visibility of octavated clefs
2725 @cindex clefs, visibility of octavation
2727 The small octavation symbol on octavated clefs is produced by the
2728 @code{OctavateEight} layout object. Its visibility is controlled
2729 independently from that of the @code{Clef} object, so it is
2730 necessary to apply any required @code{break-visibility} overrides
2731 to both the @code{Clef} and the @code{OctavateEight} layout objects
2732 to fully suppress such clef symbols at the start of each line.
2734 For explicit clef changes, the @code{explicitClefVisibility}
2735 property controls both the clef symbol and any octavation symbol
2741 @rlearning{Visibility and color of objects}
2745 @subsection Line styles
2747 Some performance indications, e.g., @i{rallentando} and
2748 @i{accelerando} and @i{trills} are written as text and are
2749 extended over many measures with lines, sometimes dotted or wavy.
2751 These all use the same routines as the glissando for drawing the
2752 texts and the lines, and tuning their behavior is therefore also
2753 done in the same way. It is done with a spanner, and the routine
2754 responsible for drawing the spanners is
2755 @code{ly:line-interface::print}. This routine determines the
2756 exact location of the two @i{span points} and draws a line
2757 between them, in the style requested.
2759 Here is an example showing the different line styles available,
2760 and how to tune them.
2762 @lilypond[relative=2,ragged-right,verbatim,fragment]
2764 \once \override Glissando #'style = #'dashed-line
2766 \override Glissando #'style = #'dotted-line
2768 \override Glissando #'style = #'zigzag
2770 \override Glissando #'style = #'trill
2774 The locations of the end-points of the spanner are computed
2775 on-the-fly for every graphic object, but it is possible to
2779 @lilypond[relative=2,ragged-right,verbatim,fragment]
2781 \once \override Glissando #'(bound-details right Y) = #-2
2785 The value for @code{Y} is set to @code{-2} for the right end
2786 point. The left side may be similarly adjusted by specifying
2787 @code{left} instead of @code{right}.
2789 If @code{Y} is not set, the value is computed from the vertical
2790 position of the left and right attachment points of the spanner.
2792 Other adjustments of spanners are possible, for details, see
2795 @node Rotating objects
2796 @subsection Rotating objects
2798 Both layout objects and elements of markup text can be rotated by
2799 any angle about any point, but the method of doing so differs.
2802 * Rotating layout objects::
2806 @node Rotating layout objects
2807 @unnumberedsubsubsec Rotating layout objects
2809 @cindex rotating objects
2810 @cindex objects, rotating
2812 All layout objects which support the @code{grob-interface} can be
2813 rotated by setting their @code{rotation} property. This takes a
2814 list of three items: the angle of rotation counter-clockwise,
2815 and the x and y coordinates of the point relative to the object's
2816 reference point about which the rotation is to be performed. The
2817 angle of rotation is specified in degrees and the coordinates in
2820 The angle of rotation and the coordinates of the rotation point must
2821 be determined by trial and error.
2823 @cindex hairpins, angled
2824 @cindex angled hairpins
2826 There are only a few situations where the rotation of layout
2827 objects is useful; the following example shows one situation where
2830 @lilypond[quote,verbatim,relative=1]
2832 \override Hairpin #'rotation = #'(20 -1 0)
2836 @node Rotating markup
2837 @unnumberedsubsubsec Rotating markup
2839 All markup text can be rotated to lie at any angle by prefixing it
2840 with the @code{\rotate} command. The command takes two arguments:
2841 the angle of rotation in degrees counter-clockwise and the text to
2842 be rotated. The extents of the text are not rotated: they take
2843 their values from the extremes of the x and y coordinates of the
2844 rotated text. In the following example the
2845 @code{outside-staff-priority} property for text is set to @code{#f}
2846 to disable the automatic collision avoidance, which would push some
2847 of the text too high.
2849 @lilypond[quote,verbatim,relative=1]
2850 \override TextScript #'outside-staff-priority = ##f
2851 g4^\markup { \rotate #30 "a G" }
2852 b^\markup { \rotate #30 "a B" }
2853 des^\markup { \rotate #30 "a D-Flat" }
2854 fis^\markup { \rotate #30 "an F-Sharp" }
2857 @node Advanced tweaks
2858 @section Advanced tweaks
2860 This section discusses various approaches to fine tuning the
2861 appearance of the printed score.
2864 * Aligning objects::
2865 * Vertical grouping of grobs::
2866 * Modifying stencils::
2867 * Modifying shapes::
2873 @rlearning{Tweaking output},
2874 @rlearning{Other sources of information}.
2877 @ref{Explaining the Internals Reference},
2878 @ref{Modifying properties},
2879 @ref{Interfaces for programmers}.
2882 @file{scm/@/define@/-grobs@/.scm}.
2885 @rlsr{Tweaks and overrides}.
2887 Internals Reference:
2888 @rinternals{All layout objects}.
2891 @node Aligning objects
2892 @subsection Aligning objects
2894 Graphical objects which support the @code{self-alignment-interface} and/or
2895 the @code{side-position-interface} can be
2896 aligned to a previously placed object in a variety of ways. For a list of these objects, see
2897 @rinternals{self-alignment-interface} and @rinternals{side-position-interface}.
2899 All graphical objects have a reference point, a horizontal extent and a
2900 vertical extent. The horizontal extent is a pair of numbers
2901 giving the displacements from the reference point of the left and
2902 right edges, displacements to the left being negative. The
2903 vertical extent is a pair of numbers giving the displacement from
2904 the reference point to the bottom and top edges, displacements down
2907 An object's position on a staff is given by the values of the
2908 @code{X-offset} and @code{Y-offset} properties. The value of
2909 @code{X-offset} gives the displacement from the x coordinate of
2910 the reference point of the parent object, and the value of
2911 @code{Y-offset} gives the displacement from the center line of the
2912 staff. The values of @code{X-offset} and
2913 @code{Y-offset} may be set directly or may be set to be calculated
2914 by procedures in order to achieve alignment with the parent object
2917 @warning{Many objects have special positioning considerations which
2918 cause any setting of @code{X-offset} or @code{Y-offset} to be
2919 ignored or modified, even though the object supports the
2920 @code{self-alignment-interface}.}
2922 For example, an accidental can be repositioned
2923 vertically by setting @code{Y-offset} but any changes to
2924 @code{X-offset} have no effect.
2926 Rehearsal marks may be aligned with
2927 breakable objects such as bar lines, clef symbols, time signature
2928 symbols and key signatures. There are special properties to be
2929 found in the @code{break-aligned-interface} for positioning rehearsal
2930 marks on such objects.
2933 * Setting @code{X-offset} and @code{Y-offset} directly::
2934 * Using the @code{side-position-interface}::
2935 * Using the @code{self-alignment-interface}::
2936 * Using the @code{break-alignable-interface}::
2939 @node Setting @code{X-offset} and @code{Y-offset} directly
2940 @unnumberedsubsubsec Setting @code{X-offset} and @code{Y-offset} directly
2942 Numerical values may be given to the @code{X-offset} and @code{Y-offset}
2943 properties of many objects. The following example shows three
2944 notes with the default fingering position and the positions with @code{X-offset}
2945 and @code{Y-offset} modified.
2947 @lilypond[verbatim,quote,relative=2]
2950 -\tweak #'X-offset #0
2951 -\tweak #'Y-offset #0
2954 -\tweak #'X-offset #-1
2955 -\tweak #'Y-offset #1
2961 @node Using the @code{side-position-interface}
2962 @unnumberedsubsubsec Using the @code{side-position-interface}
2964 An object which supports the @code{side-position-interface} can be
2965 placed next to its parent object so that
2966 the specified edges of the two objects touch. The object may be
2967 placed above, below, to the right or to the left of the parent.
2968 The parent cannot be specified; it is determined by the order of
2969 elements in the input stream. Most objects have the associated
2970 note head as their parent.
2972 The values of the @code{side-axis} and @code{direction} properties
2973 determine where the object is to be placed, as follows:
2975 @c TODO add an example of each to the table
2977 @multitable @columnfractions .3 .3 .3
2978 @headitem @code{side-axis} @tab @code{direction} @tab
2979 @headitem property @tab property @tab Placement
2981 @item @code{0} @tab @code{-1} @tab left
2982 @item @code{0} @tab @code{1} @tab right
2983 @item @code{1} @tab @code{-1} @tab below
2984 @item @code{1} @tab @code{1} @tab above
2988 When @code{side-axis} is @code{0}, @code{X-offset} should be set to
2989 the procedure @code{ly:side-position-interface::x-aligned-side}.
2990 This procedure will return the correct value of @code{X-offset} to
2991 place the object to the left or right side of the parent according
2992 to value of @code{direction}.
2994 When @code{side-axis} is @code{1}, @code{Y-offset} should be set to
2995 the procedure @code{ly:side-position-interface::y-aligned-side}.
2996 This procedure will return the correct value of @code{Y-offset} to
2997 place the object to the top or bottom of the parent according
2998 to value of @code{direction}.
3000 @c TODO Add examples
3002 @node Using the @code{self-alignment-interface}
3003 @unnumberedsubsubsec Using the @code{self-alignment-interface}
3005 @emph{Self-aligning objects horizontally}
3007 The horizontal alignment of an object which supports the
3008 @code{self-alignment-interface} is controlled by the value of
3009 the @code{self-alignment-X} property, provided the object's
3010 @code{X-offset} property is set to
3011 @code{ly:self-alignment-interface::x-aligned-on-self}.
3012 @code{self-alignment-X} may be given any
3013 real value, in units of half the total X extent of the
3014 object. Negative values move the object to the right, positive
3015 to the left. A value of @code{0} centers the object on the
3016 reference point of its parent, a value of @code{-1} aligns the
3017 left edge of the object on the reference point of its parent,
3018 and a value of @code{1} aligns the right edge of the object on the
3019 reference point of its parent. The symbols @code{LEFT},
3020 @code{CENTER} and @code{RIGHT} may be used instead of the values
3021 @code{-1, 0, 1} respectively.
3023 Normally the @code{\override} command would be used to modify the
3024 value of @code{self-alignment-X}, but the @code{\tweak} command
3025 can be used to separately align several annotations on a single
3028 @lilypond[quote,verbatim,relative=1]
3030 -\tweak #'self-alignment-X #-1
3032 -\tweak #'self-alignment-X #0
3034 -\tweak #'self-alignment-X #RIGHT
3036 -\tweak #'self-alignment-X #-2.5
3037 ^"aligned further to the right"
3040 @emph{Self-aligning objects vertically}
3042 Objects may be aligned vertically in an analogous way to aligning
3043 them horizontally if the @code{Y-offset} property is set to
3044 @code{ly:self-alignment-interface::y-aligned-on-self}. However,
3045 other mechanisms are often involved in vertical alignment: the
3046 value of @code{Y-offset} is just one variable taken into account.
3047 This may make adjusting the value of some objects tricky.
3048 The units are just half the vertical extent of the object, which
3049 is usually quite small, so quite large numbers may be required.
3050 A value of @code{-1} aligns the lower edge of the object with
3051 the reference point of the parent object, a value of @code{0}
3052 aligns the center of the object with the reference point of the
3053 parent, and a value of @code{1} aligns the top edge of the object
3054 with the reference point of the parent. The symbols @code{DOWN},
3055 @code{CENTER}, @code{UP} may be substituted for @code{-1, 0, 1}
3058 @emph{Self-aligning objects in both directions}
3060 By setting both @code{X-offset} and @code{Y-offset}, an object may
3061 be aligned in both directions simultaneously.
3063 The following example shows how to adjust a fingering mark so
3064 that it nestles close to the note head.
3066 @lilypond[quote,verbatim,relative=2]
3068 -\tweak #'self-alignment-X #0.5 % move horizontally left
3069 -\tweak #'Y-offset #ly:self-alignment-interface::y-aligned-on-self
3070 -\tweak #'self-alignment-Y #-1 % move vertically up
3075 @unnumberedsubsubsec Using the @code{aligned-on-parent} procedures
3077 @c Cannot document as they do not seem to operate consistently on all objects -td
3078 @c TODO investigate further
3080 The @code{aligned-on-parent} procedures are used in the same way
3081 as the @code{aligned-on-self} procedures, they difference being
3082 that they permit an object to be aligned with the @emph{edges} of
3083 the parent rather than the parent's reference point. The following
3084 example shows the difference:
3088 @lilypond[verbatim,quote]
3094 @unnumberedsubsubsec Using the @code{centered-on-parent} procedures
3096 @c Cannot document as they do not seem to operate consistently on all objects -td
3097 @c TODO investigate further
3101 @c TODO The align-interface, BassFigureAlignment and VerticalAlignment
3103 @node Using the @code{break-alignable-interface}
3104 @unnumberedsubsubsec Using the @code{break-alignable-interface}
3106 @cindex align to objects
3107 @cindex break-align-symbols
3109 Rehearsal marks and bar numbers may be aligned with notation
3110 objects other than bar lines. These objects include @code{ambitus},
3111 @code{breathing-sign}, @code{clef}, @code{custos}, @code{staff-bar},
3112 @code{left-edge}, @code{key-cancellation}, @code{key-signature}, and
3113 @code{time-signature}.
3115 By default, rehearsal marks and bar numbers will be horizontally
3116 centered above the object:
3118 @lilypond[verbatim,quote,relative=1]
3120 % the RehearsalMark will be centered above the Clef
3121 \override Score.RehearsalMark #'break-align-symbols = #'(clef)
3126 % the RehearsalMark will be centered above the TimeSignature
3127 \override Score.RehearsalMark #'break-align-symbols = #'(time-signature)
3135 A list of possible target alignment objects may be specified. If
3136 some of the objects are invisible at that point due to the setting
3137 of @code{break-visibility} or the explicit visibility settings for
3138 keys and clefs, the rehearsal mark or bar number is aligned to the
3139 first object in the list which is visible. If no objects in the
3140 list are visible the object is aligned to the bar line. If the bar
3141 line is invisible the object is aligned to the place where the bar
3144 @lilypond[verbatim,quote,relative=1]
3146 % the RehearsalMark will be centered above the Key Signature
3147 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature clef)
3152 % the RehearsalMark will be centered above the Clef
3153 \set Staff.explicitKeySignatureVisibility = #all-invisible
3154 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature clef)
3161 The alignment of the rehearsal mark relative to the notation object
3162 can be changed, as shown in the following example. In a score with
3163 multiple staves, this setting should be done for all the staves.
3165 @lilypond[verbatim,quote,relative=1]
3166 % The RehearsalMark will be centered above the KeySignature
3167 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature)
3173 % The RehearsalMark will be aligned with the left edge of the KeySignature
3174 \once \override Score.KeySignature #'break-align-anchor-alignment = #LEFT
3178 % The RehearsalMark will be aligned with the right edge of the KeySignature
3179 \once \override Score.KeySignature #'break-align-anchor-alignment = #RIGHT
3185 The rehearsal mark can also be offset to the right or left of the left edge
3186 by an arbitrary amount. The units are staff-spaces:
3188 @lilypond[verbatim,quote,relative=1]
3189 % The RehearsalMark will be aligned with the left edge of the KeySignature
3190 % and then shifted right by 3.5 staff-spaces
3191 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature)
3192 \once \override Score.KeySignature #'break-align-anchor = #3.5
3196 % The RehearsalMark will be aligned with the left edge of the KeySignature
3197 % and then shifted left by 2 staff-spaces
3198 \once \override Score.KeySignature #'break-align-anchor = #-2
3205 @node Vertical grouping of grobs
3206 @subsection Vertical grouping of grobs
3208 @c FIXME Expand this section
3210 The VerticalAlignment and VerticalAxisGroup grobs work together.
3211 VerticalAxisGroup groups together different grobs like Staff, Lyrics,
3212 etc. VerticalAlignment then vertically aligns the different grobs
3213 grouped together by VerticalAxisGroup. There is usually only one
3214 VerticalAlignment per score but every Staff, Lyrics, etc. has its own
3218 @node Modifying stencils
3219 @subsection Modifying stencils
3221 All layout objects have a @code{stencil} property which is part of
3222 the @code{grob-interface}. By default, this property is usually
3223 set to a function specific to the object that is tailor-made to
3224 render the symbol which represents it in the output. For example,
3225 the standard setting for the @code{stencil} property of the
3226 @code{MultiMeasureRest} object is @code{ly:multi-measure-rest::print}.
3228 The standard symbol for any object can be replaced by modifying the
3229 @code{stencil} property to reference a different, specially-written,
3230 procedure. This requires a high level of knowledge of the internal
3231 workings of LilyPond, but there is an easier way which can often
3232 produce adequate results.
3234 This is to set the @code{stencil} property to the procedure which
3235 prints text -- @code{ly:text-interface::print} -- and to add a
3236 @code{text} property to the object which is set to contain the
3237 markup text which produces the required symbol. Due to the
3238 flexibility of markup, much can be achieved -- see in particular
3239 @ref{Graphic notation inside markup}.
3241 The following example demonstrates this by changing the note head
3242 symbol to a cross within a circle.
3244 @lilypond[verbatim,quote]
3246 \once \override NoteHead #'stencil = #ly:text-interface::print
3247 \once \override NoteHead #'text = \markup {
3249 \halign #-0.7 \draw-circle #0.85 #0.2 ##f
3250 \musicglyph #"noteheads.s2cross"
3258 Any of the glyphs in the feta Font can be supplied to the
3259 @code{\musicglyph} markup command -- see @ref{The Feta font}.
3261 @c TODO Add inserting eps files or ref to later
3263 @c TODO Add inserting Postscript or ref to later
3268 @ref{Graphic notation inside markup},
3269 @ref{Formatting text},
3270 @ref{Text markup commands},
3271 @ref{The Feta font}.
3274 @node Modifying shapes
3275 @subsection Modifying shapes
3278 * Modifying ties and slurs::
3281 @node Modifying ties and slurs
3282 @unnumberedsubsubsec Modifying ties and slurs
3284 @cindex slurs, modifying
3285 @cindex ties, modifying
3286 @cindex Bézier curves
3287 @cindex Bézier control points
3289 Ties, slurs and phrasing slurs are drawn as third-order Bézier
3290 curves. If the shape of the tie or slur which is calculated
3291 automatically is not optimum, the shape may be modified manually by
3292 explicitly specifying the four control points required to define
3293 a third-order Bézier curve.
3295 Third-order or cubic Bézier curves are defined by four control
3296 points. The first and fourth control points are precisely the
3297 starting and ending points of the curve. The intermediate two
3298 control points define the shape. Animations showing how the curve
3299 is drawn can be found on the web, but the following description
3300 may be helpful. The curve starts from the first control point
3301 heading directly towards the second, gradually bending over to
3302 head towards the third and continuing to bend over to head towards
3303 the fourth, arriving there travelling directly from the third
3304 control point. The curve is entirely contained in the
3305 quadrilateral defined by the four control points.
3307 Here is an example of a case where the tie is not optimum, and
3308 where @code{\tieDown} would not help.
3310 @lilypond[verbatim,quote,relative=1]
3314 { r4 <g c,> <g c,> <g c,> }
3318 One way of improving this tie is to manually modify its control
3321 The coordinates of the Bézier control points are specified in units
3322 of staff-spaces. The X@tie{}coordinate is relative to the reference
3323 point of the note to which the tie or slur is attached, and the
3324 Y@tie{}coordinate is relative to the staff center line. The
3325 coordinates are entered as a list of four pairs of decimal numbers
3326 (reals). One approach is to estimate the coordinates of the two
3327 end points, and then guess the two intermediate points. The optimum
3328 values are then found by trial and error.
3330 It is useful to remember that a symmetric curve requires symmetric
3331 control points, and that Bézier curves have the useful property that
3332 transformations of the curve such as translation, rotation and
3333 scaling can be achieved by applying the same transformation to the
3334 curve's control points.
3336 For the example above the following override gives a satisfactory
3337 tie. Note the placement -- it has to be immediately before the note
3338 to which the start of the tie (or slur) is attached.
3340 @lilypond[verbatim,quote,relative=1]
3344 #'control-points = #'((1 . -1) (3 . 0.6) (12.5 . 0.6) (14.5 . -1))
3348 { r4 <g c,> <g c,> <g c,>4 }
3354 It is not possible to modify shapes of ties or slurs by changing
3355 the @code{control-points} property if there are more than one at
3356 the same musical moment, not even by using the @code{\tweak}