1 %%%% -*- Mode: Scheme -*-
3 %%%% This file is part of LilyPond, the GNU music typesetter.
5 %%%% Copyright (C) 2003--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
6 %%%% Jan Nieuwenhuizen <janneke@gnu.org>
8 %%%% LilyPond is free software: you can redistribute it and/or modify
9 %%%% it under the terms of the GNU General Public License as published by
10 %%%% the Free Software Foundation, either version 3 of the License, or
11 %%%% (at your option) any later version.
13 %%%% LilyPond is distributed in the hope that it will be useful,
14 %%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
15 %%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 %%%% GNU General Public License for more details.
18 %%%% You should have received a copy of the GNU General Public License
19 %%%% along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
24 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
25 %% this file is alphabetically sorted.
26 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
28 %% need SRFI-1 for filter; optargs for lambda*
29 #(use-modules (srfi srfi-1)
32 %% TODO: using define-music-function in a .scm causes crash.
35 #(define-music-function (parser location music)
37 (_i "Make @var{music} absolute. This does not actually change the
38 music itself but rather hides it from surrounding @code{\\relative}
40 (make-music 'RelativeOctaveMusic 'element music))
43 #(def-grace-function startAcciaccaturaMusic stopAcciaccaturaMusic
44 (_i "Create an acciaccatura from the following music expression"))
46 %% keep these two together
47 instrument-definitions = #'()
48 addInstrumentDefinition =
49 #(define-void-function
50 (parser location name lst) (string? list?)
51 (_i "Create instrument @var{name} with properties @var{list}.")
52 (set! instrument-definitions (acons name lst instrument-definitions)))
55 #(define-void-function (parser location name music) (string? ly:music?)
56 (_i "Define @var{music} as a quotable music expression named
58 (add-quotable parser name music))
60 %% keep these two together
61 afterGraceFraction = #(cons 6 8)
63 #(define-music-function (parser location main grace) (ly:music? ly:music?)
64 (_i "Create @var{grace} note(s) after a @var{main} music expression.")
65 (let ((main-length (ly:music-length main))
66 (fraction (ly:parser-lookup parser 'afterGraceFraction)))
67 (make-simultaneous-music
70 (make-sequential-music
73 (make-music 'SkipMusic
74 'duration (ly:make-duration
76 (* (ly:moment-main-numerator main-length)
78 (* (ly:moment-main-denominator main-length)
80 (make-music 'GraceMusic
84 %% music identifiers not allowed at top-level,
85 %% so this is a music-function instead.
87 #(define-music-function (location parser) ()
88 (_i "Allow a page turn. May be used at toplevel (ie between scores or
89 markups), or inside a score.")
90 (make-music 'EventChord
92 'page-turn-permission 'allow
93 'elements (list (make-music 'PageTurnEvent
94 'break-permission 'allow))))
97 #(define-music-function (parser location property arg item)
98 (symbol-list-or-symbol? list? symbol-list-or-music?)
99 (_i "Override @var{property} for pieces of broken spanner @var{item}
100 with values @var{arg}. @var{item} may either be music in the form of
101 a starting spanner event, or a symbol list in the form
102 @samp{Context.Grob} or just @samp{Grob}. Iff @var{item} is in the
103 form of a spanner event, @var{property} may also have the form
104 @samp{Grob.property} for specifying a directed tweak.")
106 (if (eq? (ly:music-property item 'span-direction) START)
107 #{ \tweak #property #(value-for-spanner-piece arg) #item #}
109 (ly:music-warning item (_ "not a spanner"))
111 (let* ((p (check-grob-path item parser location
115 (name (and p (second p)))
117 (and name (assoc-get name all-grob-descriptions))))
119 (member 'spanner-interface
120 (assoc-get 'interfaces
121 (assoc-get 'meta description))))
123 \override #item . #property =
124 #(value-for-spanner-piece arg)
127 (ly:input-warning location (_ "not a spanner name, `~a'") name)
128 (make-music 'Music))))))
131 #(define-music-function (parser location tag more music)
132 (symbol? ly:music? ly:music?)
133 (_i "Append @var{more} to the @code{elements} of all music
134 expressions in @var{music} that are tagged with @var{tag}.")
135 (music-map (lambda (m)
136 (if (memq tag (ly:music-property m 'tags))
137 (set! (ly:music-property m 'elements)
138 (append (ly:music-property m 'elements)
144 #(define-music-function (parser location proc) (procedure?)
145 (_i "Modify context properties with Scheme procedure @var{proc}.")
146 (make-music 'ApplyContext
150 #(define-music-function (parser location func music) (procedure? ly:music?)
151 (_i"Apply procedure @var{func} to @var{music}.")
155 #(define-music-function (parser location ctx proc) (symbol? procedure?)
156 (_i "Apply function @code{proc} to every layout object in context @code{ctx}")
157 (make-music 'ApplyOutputEvent
162 #(def-grace-function startAppoggiaturaMusic stopAppoggiaturaMusic
163 (_i "Create an appoggiatura from @var{music}"))
165 % for regression testing purposes.
167 #(define-music-function (parser location l r) (pair? pair?)
168 (_i "Testing function: check whether the beam quants @var{l} and @var{r} are correct")
169 (make-grob-property-override 'Beam 'positions (check-quant-callbacks l r)))
171 % for regression testing purposes.
173 #(define-music-function (parser location comp) (procedure?)
174 (_i "Testing function: check whether the slope of the beam is the same as @code{comp}")
175 (make-grob-property-override 'Beam 'positions (check-slope-callbacks comp)))
178 #(define-music-function (parser location music) (ly:music?)
179 (_i "Make voices that switch between staves automatically")
180 (make-autochange-music parser music))
185 #(define-music-function (parser location grob-name offset text)
186 (symbol? number-pair? markup?)
187 (_i "Attach @var{text} to @var{grob-name} at offset @var{offset}
188 (use like @code{\\once})")
191 (make-music 'AnnotateOutputEvent
193 'X-offset (car offset)
194 'Y-offset (cdr offset)
198 #(define-event-function (parser location offset text) (number-pair? markup?)
199 (_i "Attach @var{text} at @var{offset} (use like @code{\\tweak})")
200 (make-music 'AnnotateOutputEvent
201 'X-offset (car offset)
202 'Y-offset (cdr offset)
206 #(define-music-function (parser location type) (string?)
207 (_i "Insert a bar line of type @var{type}")
209 (make-property-set 'whichBar type)
213 #(define-music-function (parser location n) (integer?)
214 (_i "Print a warning if the current bar number is not @var{n}.")
215 (make-music 'ApplyContext
218 (let ((cbn (ly:context-property c 'currentBarNumber)))
219 (if (and (number? cbn) (not (= cbn n)))
220 (ly:input-warning location
221 "Barcheck failed got ~a expect ~a"
225 #(define-event-function (parser location delta) (real?)
226 (_i "Create a fall or doit of pitch interval @var{delta}.")
227 (make-music 'BendAfterEvent
231 #(define-void-function (parser location newfilename) (string?)
232 (_i "Direct output for the current book block to @var{newfilename}.")
233 (set! (paper-variable parser #f 'output-filename) newfilename))
236 #(define-void-function (parser location newsuffix) (string?)
237 (_i "Set the output filename suffix for the current book block to
239 (set! (paper-variable parser #f 'output-suffix) newsuffix))
241 %% \breathe is defined as a music function rather than an event identifier to
242 %% ensure it gets useful input location information: as an event identifier,
243 %% it would have to be wrapped in an EventChord to prevent it from being
244 %% treated as a post_event by the parser
246 #(define-music-function (parser location) ()
247 (_i "Insert a breath mark.")
248 (make-music 'BreathingEvent))
251 #(define-music-function (parser location type) (string?)
252 (_i "Set the current clef to @var{type}.")
253 (make-clef-set type))
257 #(define-music-function (parser location args) (pair?)
258 (_i "Create compound time signatures. The argument is a Scheme list of
259 lists. Each list describes one fraction, with the last entry being the
260 denominator, while the first entries describe the summands in the
261 enumerator. If the time signature consists of just one fraction,
262 the list can be given directly, i.e. not as a list containing a single list.
263 For example, a time signature of (3+1)/8 + 2/4 would be created as
264 @code{\\compoundMeter #'((3 1 8) (2 4))}, and a time signature of (3+2)/8
265 as @code{\\compoundMeter #'((3 2 8))} or shorter
266 @code{\\compoundMeter #'(3 2 8)}.")
267 (let* ((mlen (calculate-compound-measure-length args))
268 (beat (calculate-compound-base-beat args))
269 (beatGrouping (calculate-compound-beat-grouping args))
270 (timesig (cons (ly:moment-main-numerator mlen)
271 (ly:moment-main-denominator mlen))))
273 \once \override Staff.TimeSignature.stencil = #(lambda (grob)
274 (grob-interpret-markup grob (format-compound-time args)))
275 \set Timing.timeSignatureFraction = #timesig
276 \set Timing.baseMoment = #beat
277 \set Timing.beatStructure = #beatGrouping
278 \set Timing.beamExceptions = #'()
279 \set Timing.measureLength = #mlen
283 #(define-music-function (parser location notes) (ly:music?)
284 (_i "Create cross-staff stems")
286 \temporary \override Stem.cross-staff = #cross-staff-connect
287 \temporary \override Flag.style = #'no-flag
289 \revert Stem.cross-staff
294 #(define-music-function (parser location type) (string?)
295 (_i "Set the current cue clef to @var{type}.")
296 (make-cue-clef-set type))
299 #(define-music-function (parser location) ()
300 (_i "Unset the current cue clef.")
301 (make-cue-clef-unset))
304 #(define-music-function
305 (parser location what dir main-music) (string? ly:dir? ly:music?)
306 (_i "Insert contents of quote @var{what} corresponding to @var{main-music},
307 in a CueVoice oriented by @var{dir}.")
308 (make-music 'QuoteMusic
310 'quoted-context-type 'CueVoice
311 'quoted-context-id "cue"
312 'quoted-music-name what
313 'quoted-voice-direction dir))
316 #(define-music-function
317 (parser location what dir clef main-music) (string? ly:dir? string? ly:music?)
318 (_i "Insert contents of quote @var{what} corresponding to @var{main-music},
319 in a CueVoice oriented by @var{dir}.")
320 (make-music 'QuoteMusic
322 'quoted-context-type 'CueVoice
323 'quoted-context-id "cue"
324 'quoted-music-name what
325 'quoted-music-clef clef
326 'quoted-voice-direction dir))
331 #(define-music-function (parser location music) (ly:music?)
332 (_i "Display the LilyPond input representation of @var{music}
335 (display-lily-music music parser)
339 #(define-music-function (parser location music) (ly:music?)
340 (_i "Display the internal representation of @var{music} to the console.")
342 (display-scheme-music music)
346 #(define-scheme-function (parser location expr) (scheme?)
347 (_i "Display the internal representation of @var{expr} to the console.")
349 (display-scheme-music expr)
355 #(define-music-function (parser location music) (ly:music?)
356 (_i "Terminate the next spanner prematurely after exactly one note
357 without the need of a specific end spanner.")
358 (let* ((start-span-evs (filter (lambda (ev)
359 (equal? (ly:music-property ev 'span-direction)
361 (extract-typed-music music 'span-event)))
364 (music-clone m 'span-direction STOP))
366 (end-ev-chord (make-music 'EventChord
367 'elements stop-span-evs))
368 (total (make-music 'SequentialMusic
369 'elements (list music
374 #(define-music-function (parser location music) (ly:music?)
375 (_i "Compatibility function wrapping @code{EventChord} around
376 isolated rhythmic events occuring since version 2.15.28, after
377 expanding repeat chords @samp{q}.")
378 (event-chord-wrap! music parser))
381 #(define-music-function (parser location factor argument) (ly:moment? ly:music?)
382 (_i "Adjust durations of music in @var{argument} by rational @var{factor}.")
383 (let ((orig-duration (ly:music-length argument))
384 (multiplier (ly:make-moment 1 1)))
388 (if (< 0 (ly:moment-main-denominator (ly:music-length mus)))
390 (ly:music-compress mus multiplier)
391 (set! multiplier (ly:moment-mul factor multiplier)))))
392 (extract-named-music argument '(EventChord NoteEvent RestEvent SkipEvent)))
395 (ly:moment-div orig-duration (ly:music-length argument)))
400 #(define-event-function (parser location finger) (number-or-markup?)
401 (_i "Apply @var{finger} as a fingering indication.")
405 (if (number? finger) 'digit 'text)
409 #(define-music-function (parser location mark offset footnote item)
410 ((markup?) number-pair? markup? symbol-list-or-music?)
411 (_i "Make the markup @var{footnote} a footnote on @var{item}. The
412 footnote is marked with a markup @var{mark} moved by @var{offset} with
413 respect to the marked music.
415 If @var{mark} is not given or specified as @var{\\default}, it is
416 replaced by an automatically generated sequence number. If @var{item}
417 is a symbol list of form @samp{Grob} or @samp{Context.Grob}, then
418 grobs of that type will be marked at the current time step in the
419 given context (default @code{Bottom}).
421 If @var{item} is music, the music will get a footnote attached to a
422 grob immediately attached to the event, like @var{\\tweak} does. For
423 attaching a footnote to an @emph{indirectly} caused grob, write
424 @code{\\single\\footnote}, use @var{item} to specify the grob, and
425 follow it with the music to annotate.
427 Like with @code{\\tweak}, if you use a footnote on a following
428 post-event, the @code{\\footnote} command itself needs to be attached
429 to the preceding note or rest as a post-event with @code{-}.")
430 (let ((mus (make-music
432 'X-offset (car offset)
433 'Y-offset (cdr offset)
434 'automatically-numbered (not mark)
435 'text (or mark (make-null-markup))
436 'footnote-text footnote)))
437 #{ \tweak footnote-music #mus #item #}))
440 #(def-grace-function startGraceMusic stopGraceMusic
441 (_i "Insert @var{music} as grace notes."))
444 #(define-scheme-function (parser location descriptions) (list?)
445 (_i "Create a context modification from @var{descriptions}, a list
446 in the format of @code{all-grob-descriptions}.")
449 (list 'assign (car p) (list (cdr p))))
452 harmonicByFret = #(define-music-function (parser location fret music) (number? ly:music?)
453 (_i "Convert @var{music} into mixed harmonics; the resulting notes resemble
454 harmonics played on a fretted instrument by touching the strings at @var{fret}.")
456 \set harmonicDots = ##t
457 \temporary \override TabNoteHead.stencil = #(tab-note-head::print-custom-fret-label (number->string fret))
458 \temporary \override NoteHead.Y-extent = #grob::always-Y-extent-from-stencil
459 \temporary \override NoteHead.stencil = #(lambda (grob) (ly:grob-set-property! grob 'style 'harmonic-mixed)
460 (ly:note-head::print grob))
462 (calc-harmonic-pitch (fret->pitch (number->string fret)) music))
464 \revert TabNoteHead.stencil
465 \revert NoteHead.Y-extent
466 \revert NoteHead.stencil
469 harmonicByRatio = #(define-music-function (parser location ratio music) (number? ly:music?)
470 (_i "Convert @var{music} into mixed harmonics; the resulting notes resemble
471 harmonics played on a fretted instrument by touching the strings at the point
472 given through @var{ratio}.")
474 \set harmonicDots = ##t
475 \temporary \override TabNoteHead.stencil = #(tab-note-head::print-custom-fret-label (ratio->fret ratio))
476 \temporary \override NoteHead.Y-extent = #(ly:make-unpure-pure-container ly:grob::stencil-height
477 (lambda (grob start end)
478 (ly:grob::stencil-height grob)))
479 \temporary \override NoteHead.stencil = #(lambda (grob) (ly:grob-set-property! grob 'style 'harmonic-mixed)
480 (ly:note-head::print grob))
482 (calc-harmonic-pitch (ratio->pitch ratio) music))
484 \revert TabNoteHead.stencil
485 \revert NoteHead.Y-extent
486 \revert NoteHead.stencil
490 #(define-music-function (parser location item) (symbol-list-or-music?)
491 (_i "Set @var{item}'s @samp{transparent} property to @code{#t},
492 making it invisible while still retaining its dimensions.
494 If @var{item} is a symbol list of form @code{GrobName} or
495 @code{Context.GrobName}, the result is an override for the grob name
496 specified by it. If @var{item} is a music expression, the result is
497 the same music expression with an appropriate tweak applied to it.")
499 #{ \tweak transparent ##t #item #}
500 #{ \override #item . transparent = ##t #}))
503 #(define-music-function (parser location) ()
504 (_i "Put the segno variant 'varsegno' at this position into the staff,
505 compatible with the repeat command.")
506 (make-music 'ApplyContext
509 (let ((score-ctx (ly:context-find ctx 'Score)))
510 (if (ly:context? score-ctx)
511 (let ((old-rc (ly:context-property score-ctx 'repeatCommands '())))
512 (if (eq? (memq 'segno-display old-rc) #f)
513 (ly:context-set-property! score-ctx 'repeatCommands (cons 'segno-display old-rc)))))))))
516 #(define-music-function
517 (parser location name) (string?)
518 (_i "Switch instrument to @var{name}, which must be predefined with
519 @code{\\addInstrumentDefinition}.")
520 (let* ((handle (assoc name instrument-definitions))
521 (instrument-def (if handle (cdr handle) '())))
524 (ly:input-warning location "No such instrument: ~a" name))
526 (make-music 'SimultaneousMusic
538 #(define-music-function (parser location tag music)
539 (symbol-list-or-symbol? ly:music?)
540 (_i "Include only elements of @var{music} that are either untagged
541 or tagged with one of the tags in @var{tag}. @var{tag} may be either
542 a single symbol or a list of symbols.")
546 (let ((music-tags (ly:music-property m 'tags)))
547 (or (null? music-tags)
548 (memq tag music-tags))))
550 (let ((music-tags (ly:music-property m 'tags)))
551 (or (null? music-tags)
552 (any (lambda (t) (memq t music-tags)) tag)))))
556 #(define-music-function (parser location tonic pitch-alist)
557 ((ly:pitch? '()) (list? '()))
558 (_i "Set key to @var{tonic} and scale @var{pitch-alist}.
559 If both are null, just generate @code{KeyChangeEvent}.")
560 (cond ((null? tonic) (make-music 'KeyChangeEvent))
562 (ly:parser-error parser (_ "second argument must be pitch list")
564 (make-music 'SequentialMusic 'void #t))
567 (make-music 'KeyChangeEvent
568 'tonic (ly:make-pitch 0 0 0)
569 'pitch-alist pitch-alist)
573 #(define-music-function (parser location music) (ly:music?)
574 (_i "Remove cue notes from @var{music}.")
577 (if (and (string? (ly:music-property mus 'quoted-music-name))
578 (string=? (ly:music-property mus 'quoted-context-id "") "cue"))
579 (ly:music-property mus 'element)
586 #(define-music-function (parser location label) (symbol?)
587 (_i "Create @var{label} as a bookmarking label.")
588 (make-music 'EventChord
591 'elements (list (make-music 'LabelEvent
592 'page-label label))))
596 #(define-void-function (parser location language) (string?)
597 (_i "Set note names for language @var{language}.")
598 (note-names-language parser language))
600 languageSaveAndChange =
601 #(define-void-function (parser location language) (string?)
602 (_i "Store the previous pitchnames alist, and set a new one.")
603 (set! previous-pitchnames pitchnames)
604 (note-names-language parser language))
607 #(define-void-function (parser location) ()
608 (_i "Restore a previously-saved pitchnames alist.")
609 (if previous-pitchnames
611 (set! pitchnames previous-pitchnames)
612 (ly:parser-set-note-names parser pitchnames))
613 (ly:input-warning location (_ "No other language was defined previously. Ignoring."))))
617 #(define-music-function (parser location arg) (ly:music?)
618 (_i "Display chords in @var{arg} as clusters.")
619 (music-map note-to-cluster arg))
622 #(define-music-function (parser location around to scale music)
623 (ly:pitch? ly:pitch? ly:music? ly:music?)
624 (_i "Invert @var{music} about @var{around} using @var{scale} and
625 transpose from @var{around} to @var{to}.")
626 (let ((inverter (make-modal-inverter around to scale)))
627 (change-pitches music inverter)
631 #(define-music-function (parser location from to scale music)
632 (ly:pitch? ly:pitch? ly:music? ly:music?)
633 (_i "Transpose @var{music} from pitch @var{from} to pitch @var{to}
635 (let ((transposer (make-modal-transposer from to scale)))
636 (change-pitches music transposer)
640 #(define-music-function
641 (parser location around to music) (ly:pitch? ly:pitch? ly:music?)
642 (_i "Invert @var{music} about @var{around} and
643 transpose from @var{around} to @var{to}.")
644 (music-invert around to music))
647 #(define-music-function
648 (parser location label) ((scheme? '()))
649 "Make the music for the \\mark command."
650 (let* ((set (and (integer? label)
651 (context-spec-music (make-property-set 'rehearsalMark label)
653 (ev (make-music 'MarkEvent
657 (make-sequential-music (list set ev))
659 (set! (ly:music-property ev 'label) label)
663 #(define-music-function (parser location proc mus) (procedure? ly:music?)
664 (_i "Apply @var{proc} to @var{mus} and all of the music it contains.")
665 (music-map proc mus))
667 %% noPageBreak and noPageTurn are music functions (not music indentifiers),
668 %% because music identifiers are not allowed at top-level.
670 #(define-music-function (location parser) ()
671 (_i "Forbid a page break. May be used at toplevel (i.e., between scores or
672 markups), or inside a score.")
673 (make-music 'EventChord
675 'page-break-permission 'forbid
676 'elements (list (make-music 'PageBreakEvent
677 'break-permission '()))))
680 #(define-music-function (location parser) ()
681 (_i "Forbid a page turn. May be used at toplevel (i.e., between scores or
682 markups), or inside a score.")
683 (make-music 'EventChord
685 'page-turn-permission 'forbid
686 'elements (list (make-music 'PageTurnEvent
687 'break-permission '()))))
692 #(define-music-function (parser location pitch) (ly:pitch?)
694 (make-music 'RelativeOctaveCheck
698 #(define-music-function (parser location property offsets item)
699 (symbol-list-or-symbol? scheme? symbol-list-or-music?)
700 (_i "Offset the default value of @var{property} of @var{item} by
701 @var{offsets}. If @var{item} is a string, the result is
702 @code{\\override} for the specified grob type. If @var{item} is
703 a music expression, the result is the same music expression with an
704 appropriate tweak applied.")
706 #{ \tweak #property #(offsetter property offsets) #item #}
707 (if (check-grob-path item parser location
712 \override #item . #property =
713 #(offsetter property offsets)
715 (make-music 'Music))))
718 #(define-music-function (parser location item) (symbol-list-or-music?)
719 (_i "Set @var{item}'s @samp{stencil} property to @code{#f},
720 effectively omitting it without taking up space.
722 If @var{item} is a symbol list of form @code{GrobName} or
723 @code{Context.GrobName}, the result is an override for the grob name
724 specified by it. If @var{item} is a music expression, the result is
725 the same music expression with an appropriate tweak applied to it.")
727 #{ \tweak stencil ##f #item #}
728 #{ \override #item . stencil = ##f #}))
731 #(define-music-function (parser location music) (ly:music?)
732 (_i "Set @code{once} to @code{#t} on all layout instruction events in @var{music}.")
735 (cond ((music-is-of-type? m 'layout-instruction-event)
736 (set! (ly:music-property m 'once) #t))
737 ((ly:duration? (ly:music-property m 'duration))
738 (ly:music-warning m (_ "Cannot apply \\once to timed music"))))
743 #(define-music-function (parser location octave) (integer?)
744 (_i "Set the octavation.")
745 (make-music 'OttavaMusic
746 'ottava-number octave))
748 overrideTimeSignatureSettings =
749 #(define-music-function
750 (parser location time-signature base-moment beat-structure beam-exceptions)
751 (fraction? fraction? list? list?)
753 (_i "Override @code{timeSignatureSettings}
754 for time signatures of @var{time-signature} to have settings
755 of @var{base-moment}, @var{beat-structure}, and @var{beam-exceptions}.")
757 ;; TODO -- add warning if largest value of grouping is
758 ;; greater than time-signature.
759 (let ((setting (make-setting base-moment beat-structure beam-exceptions)))
760 (override-time-signature-setting time-signature setting)))
763 #(define-music-function (parser location grob-property-path value)
764 (symbol-list? scheme?)
766 (_i "Set the grob property specified by @var{grob-property-path} to
767 @var{value}. @var{grob-property-path} is a symbol list of the form
768 @code{Context.GrobName.property} or @code{GrobName.property}, possibly
769 with subproperties given as well.")
770 (let ((p (check-grob-path grob-property-path parser location
774 (make-music 'ApplyOutputEvent
775 'context-type (first p)
777 (lambda (grob orig-context context)
779 (cdr (assoc 'name (ly:grob-property grob 'meta)))
781 (ly:grob-set-nested-property!
782 grob (cddr p) value))))
783 (make-music 'Music))))
790 %% pageBreak and pageTurn are music functions (iso music indentifiers),
791 %% because music identifiers are not allowed at top-level.
793 #(define-music-function (location parser) ()
794 (_i "Force a page break. May be used at toplevel (i.e., between scores or
795 markups), or inside a score.")
796 (make-music 'EventChord
798 'line-break-permission 'force
799 'page-break-permission 'force
800 'elements (list (make-music 'LineBreakEvent
801 'break-permission 'force)
802 (make-music 'PageBreakEvent
803 'break-permission 'force))))
806 #(define-music-function (location parser) ()
807 (_i "Force a page turn between two scores or top-level markups.")
808 (make-music 'EventChord
810 'line-break-permission 'force
811 'page-break-permission 'force
812 'page-turn-permission 'force
813 'elements (list (make-music 'LineBreakEvent
814 'break-permission 'force)
815 (make-music 'PageBreakEvent
816 'break-permission 'force)
817 (make-music 'PageTurnEvent
818 'break-permission 'force))))
821 #(define-void-function (parser location voice-ids music) (list? ly:music?)
822 (_i "Define parallel music sequences, separated by '|' (bar check signs),
823 and assign them to the identifiers provided in @var{voice-ids}.
825 @var{voice-ids}: a list of music identifiers (symbols containing only letters)
827 @var{music}: a music sequence, containing BarChecks as limiting expressions.
832 \\parallelMusic #'(A B C) {
842 (define (bar-check? m)
843 "Checks whether m is a bar check."
844 (eq? (ly:music-property m 'name) 'BarCheck))
845 (define (recurse-and-split music)
846 "This returns either a list of music split along barchecks, or
848 (let ((elt (ly:music-property music 'element))
849 (elts (ly:music-property music 'elements)))
850 (cond ((ly:music? elt)
851 (let ((lst (recurse-and-split elt)))
855 (let ((res (music-clone music 'element x)))
856 (if (ly:input-location?
857 (ly:music-property x 'origin))
858 (set! (ly:music-property res 'origin)
859 (ly:music-property x 'origin)))
862 ((any bar-check? elts)
863 (let* ((voices (apply circular-list
864 (make-list (length voice-ids)
866 (current-voices voices)
867 (current-sequence '()))
870 (define (push-music m)
871 "Push the music expression into the current sequence"
872 (set! current-sequence (cons m current-sequence)))
873 (define (change-voice)
874 "Stores the previously built sequence into the current voice and
875 change to the following voice."
876 (set-car! current-voices
877 (cons (reverse! current-sequence)
878 (car current-voices)))
879 (set! current-sequence '())
880 (set! current-voices (cdr current-voices)))
881 (for-each (lambda (m)
882 (let ((split? (recurse-and-split m)))
891 (if (bar-check? m) (change-voice))))))
893 (if (pair? current-sequence) (change-voice))
894 ;; un-circularize `voices' and reorder the voices
896 (set! voices (map reverse!
897 (list-head voices (length voice-ids))))
899 ;; check sequence length
900 (apply for-each (lambda seqs
901 (define (seq-len seq)
902 (reduce ly:moment-add
904 (map ly:music-length seq)))
905 (let ((moment-reference (seq-len (car seqs))))
906 (for-each (lambda (seq)
907 (if (not (equal? (seq-len seq)
913 (_ "Bars in parallel music don't have the same length"))))
918 (set! lst (concatenate! lst))
919 (let ((res (music-clone music 'elements lst)))
921 (ly:input-location? (ly:music-property
924 (set! (ly:music-property res 'origin)
925 (ly:music-property (car lst) 'origin)))
929 (let ((voices (recurse-and-split music)))
932 ;; bind voice identifiers to the voices
933 (for-each (lambda (voice-id voice)
934 (ly:parser-define! parser voice-id voice))
936 (ly:music-warning music
937 (_ "ignoring parallel music without barchecks")))))
940 #(define-music-function (parser loc arg) (ly:music?)
941 (_i "Tag @var{arg} to be parenthesized.")
943 (if (memq 'event-chord (ly:music-property arg 'types))
944 ;; arg is an EventChord -> set the parenthesize property
945 ;; on all child notes and rests
948 (if (or (memq 'note-event (ly:music-property ev 'types))
949 (memq 'rest-event (ly:music-property ev 'types)))
950 (set! (ly:music-property ev 'parenthesize) #t)))
951 (ly:music-property arg 'elements))
952 ;; No chord, simply set property for this expression:
953 (set! (ly:music-property arg 'parenthesize) #t))
957 #(define-music-function (parser location part1 part2) (ly:music? ly:music?)
958 (_i "Take the music in @var{part1} and @var{part2} and typeset so
959 that they share a staff.")
960 (make-part-combine-music parser
961 (list part1 part2) #f))
964 #(define-music-function (parser location part1 part2) (ly:music? ly:music?)
965 (_i "Take the music in @var{part1} and @var{part2} and typeset so
966 that they share a staff with stems directed upward.")
967 (make-part-combine-music parser
968 (list part1 part2) UP))
971 #(define-music-function (parser location part1 part2) (ly:music? ly:music?)
972 (_i "Take the music in @var{part1} and @var{part2} and typeset so
973 that they share a staff with stems directed downward.")
974 (make-part-combine-music parser
975 (list part1 part2) DOWN))
978 #(define-music-function (location parser type once) (symbol-or-boolean? boolean?)
979 (_i "Override the part-combiner.")
980 (make-music 'EventChord
981 'elements (list (make-music 'PartCombineForceEvent
984 partcombineApart = \partcombineForce #'apart ##f
985 partcombineApartOnce = \partcombineForce #'apart ##t
986 partcombineChords = \partcombineForce #'chords ##f
987 partcombineChordsOnce = \partcombineForce #'chords ##t
988 partcombineUnisono = \partcombineForce #'unisono ##f
989 partcombineUnisonoOnce = \partcombineForce #'unisono ##t
990 partcombineSoloI = \partcombineForce #'solo1 ##f
991 partcombineSoloIOnce = \partcombineForce #'solo1 ##t
992 partcombineSoloII = \partcombineForce #'solo2 ##f
993 partcombineSoloIIOnce = \partcombineForce #'solo2 ##t
994 partcombineAutomatic = \partcombineForce ##f ##f
995 partcombineAutomaticOnce = \partcombineForce ##f ##t
998 #(define-music-function (parser location dur) (ly:duration?)
999 (_i "Make a partial measure.")
1001 ;; We use `descend-to-context' here instead of `context-spec-music' to
1002 ;; ensure \partial still works if the Timing_translator is moved
1004 (context-spec-music (make-music 'PartialSet
1011 #(define-music-function
1012 (parser location main-note secondary-note)
1013 (ly:music? ly:music?)
1014 (_i "Print a trill with @var{main-note} as the main note of the trill and
1015 print @var{secondary-note} as a stemless note head in parentheses.")
1016 (let* ((get-notes (lambda (ev-chord)
1017 (extract-named-music ev-chord 'NoteEvent)))
1018 (sec-note-events (get-notes secondary-note))
1019 (trill-events (extract-named-music main-note 'TrillSpanEvent)))
1020 (if (pair? sec-note-events)
1022 (let* ((trill-pitch (ly:music-property (car sec-note-events) 'pitch))
1023 (forced (ly:music-property (car sec-note-events) 'force-accidental)))
1025 (if (ly:pitch? trill-pitch)
1026 (for-each (lambda (m)
1027 (ly:music-set-property! m 'pitch trill-pitch)) trill-events)
1029 (ly:input-warning location (_ "Second argument of \\pitchedTrill should be single note: "))
1030 (display sec-note-events)))
1033 (for-each (lambda (m)
1034 (ly:music-set-property! m 'force-accidental forced))
1039 #(define-music-function (parser location tag more music)
1040 (symbol? ly:music? ly:music?)
1041 (_i "Add @var{more} to the front of @code{elements} of all music
1042 expressions in @var{music} that are tagged with @var{tag}.")
1043 (music-map (lambda (m)
1044 (if (memq tag (ly:music-property m 'tags))
1045 (set! (ly:music-property m 'elements)
1046 (cons more (ly:music-property m 'elements))))
1051 #(define-music-function (parser location what main-music) (string? ly:music?)
1052 (_i "Indicate a section of music to be quoted. @var{what} indicates the name
1053 of the quoted voice, as specified in an @code{\\addQuote} command.
1054 @var{main-music} is used to indicate the length of music to be quoted;
1055 usually contains spacers or multi-measure rests.")
1056 (make-music 'QuoteMusic
1058 'quoted-music-name what))
1061 #(define-music-function (parser location pitch music)
1062 ((ly:pitch?) ly:music?)
1063 (_i "Make @var{music} relative to @var{pitch}. If @var{pitch} is
1064 omitted, the first note in @var{music} is given in absolute pitch.")
1065 ;; When \relative has no clear decision (can only happen with
1066 ;; scales with an even number of steps), it goes down (see
1067 ;; pitch.cc). The following formula puts out f for both the normal
1068 ;; 7-step scale as well as for a "shortened" scale missing the
1069 ;; final b. In either case, a first note of c will end up as c,
1070 ;; namely pitch (-1, 0, 0).
1071 (ly:make-music-relative! music
1076 ;; size of current scale:
1077 (ly:pitch-steps (ly:make-pitch 1 0))
1079 (make-music 'RelativeOctaveMusic
1083 #(define-music-function (parser location tag music)
1084 (symbol-list-or-symbol? ly:music?)
1085 (_i "Remove elements of @var{music} that are tagged with one of the
1086 tags in @var{tag}. @var{tag} may be either a single symbol or a list
1091 (not (memq tag (ly:music-property m 'tags))))
1093 (let ((music-tags (ly:music-property m 'tags)))
1094 (or (null? music-tags)
1095 (not (any (lambda (t) (memq t music-tags)) tag))))))
1098 resetRelativeOctave =
1099 #(define-music-function (parser location pitch) (ly:pitch?)
1100 (_i "Set the octave inside a \\relative section.")
1102 (make-music 'SequentialMusic
1103 'to-relative-callback
1104 (lambda (music last-pitch) pitch)))
1107 #(define-music-function (parser location music)
1109 (_i "Return @var{music} in reverse order.")
1110 (retrograde-music music))
1112 revertTimeSignatureSettings =
1113 #(define-music-function
1114 (parser location time-signature)
1117 (_i "Revert @code{timeSignatureSettings}
1118 for time signatures of @var{time-signature}.")
1119 (revert-time-signature-setting time-signature))
1122 #(define-event-function (parser location finger) (number-or-markup?)
1123 (_i "Apply @var{finger} as a fingering indication.")
1127 (if (number? finger) 'digit 'text)
1131 #(define-music-function (parser location fraction music)
1132 (fraction? ly:music?)
1133 (_i "Multiply the duration of events in @var{music} by @var{fraction}.")
1134 (ly:music-compress music
1135 (ly:make-moment (car fraction) (cdr fraction))))
1138 #(define-scheme-function (parser location ctx music)
1139 ((symbol?) ly:music?)
1140 (_i "Take the layout instruction events from @var{music}, optionally
1141 restricted to those applying to context type @var{ctx}, and return
1142 a context modification duplicating their effect.")
1143 (let ((mods (ly:make-context-mod)))
1145 (if (music-is-of-type? m 'layout-instruction-event)
1148 (case (ly:music-property m 'name)
1151 (ly:music-property m 'symbol)
1152 (ly:music-property m 'value)))
1155 (ly:music-property m 'symbol)))
1158 (ly:music-property m 'symbol)
1159 (ly:music-property m 'grob-value)
1161 ((ly:music-property m 'grob-property #f) => list)
1163 (ly:music-property m 'grob-property-path)))))
1166 (ly:music-property m 'symbol)
1168 ((ly:music-property m 'grob-property #f) => list)
1170 (ly:music-property m 'grob-property-path)))))))
1171 (case (ly:music-property m 'name)
1173 (ly:add-context-mod mods
1175 (ly:music-property m 'procedure))))
1176 ((ContextSpeccedMusic)
1178 (eq? ctx (ly:music-property m 'context-type)))
1179 (musicop (ly:music-property m 'element))))
1181 (let ((callback (ly:music-property m 'elements-callback)))
1182 (if (procedure? callback)
1183 (for-each musicop (callback m))))))))
1188 #(define-music-function (parser location offsets item)
1189 (list? symbol-list-or-music?)
1190 (_i "Offset control-points of @var{item} by @var{offsets}. The
1191 argument is a list of number pairs or list of such lists. Each
1192 element of a pair represents an offset to one of the coordinates of a
1193 control-point. If @var{item} is a string, the result is
1194 @code{\\once\\override} for the specified grob type. If @var{item} is
1195 a music expression, the result is the same music expression with an
1196 appropriate tweak applied.")
1197 (define (shape-curve grob)
1198 (let* ((orig (ly:grob-original grob))
1199 (siblings (if (ly:spanner? grob)
1200 (ly:spanner-broken-into orig) '()))
1201 (total-found (length siblings))
1202 (function (assoc-get 'control-points
1203 (reverse (ly:grob-basic-properties grob))))
1204 (coords (function grob)))
1206 (define (offset-control-points offsets)
1210 (lambda (x y) (coord-translate x y))
1213 (define (helper sibs offs)
1215 (if (eq? (car sibs) grob)
1216 (offset-control-points (car offs))
1217 (helper (cdr sibs) (cdr offs)))
1220 ;; we work with lists of lists
1221 (if (or (null? offsets)
1222 (not (list? (car offsets))))
1223 (set! offsets (list offsets)))
1225 (if (>= total-found 2)
1226 (helper siblings offsets)
1227 (offset-control-points (car offsets)))))
1228 #{ \tweak control-points #shape-curve #item #})
1231 #(define-music-function (parser location dur dots arg)
1232 (integer? integer? ly:music?)
1233 (_i "Change the duration of @var{arg} by adding @var{dur} to the
1234 @code{durlog} of @var{arg} and @var{dots} to the @code{dots} of @var{arg}.")
1238 (shift-one-duration-log x dur dots)) arg))
1241 #(define-music-function (parser location overrides music)
1242 (ly:music? ly:music?)
1243 (_i "Convert @var{overrides} to tweaks and apply them to @var{music}.
1244 This does not convert @code{\\revert}, @code{\\set} or @code{\\unset}.")
1245 (set! (ly:music-property music 'tweaks)
1247 (lambda (m) (eq? (ly:music-property m 'name)
1251 ((ly:music-property m 'grob-property #f) => list)
1253 (ly:music-property m 'grob-property-path)))))
1254 (acons (cons (ly:music-property m 'symbol) ;grob name
1256 p ;grob property path
1257 (car p))) ;grob property
1258 (ly:music-property m 'grob-value)
1260 (ly:music-property music 'tweaks)
1265 #(define-music-function (parser location dur) (ly:duration?)
1266 (_i "Skip forward by @var{dur}.")
1267 (make-music 'SkipMusic
1272 #(def-grace-function startSlashedGraceMusic stopSlashedGraceMusic
1273 (_i "Create slashed graces (slashes through stems, but no slur) from
1274 the following music expression"))
1277 #(define-music-function (parser location parameters) (list?)
1278 (_i "Set the system stretch, by reading the 'system-stretch property of
1279 the `parameters' assoc list.")
1281 \overrideProperty Score.NonMusicalPaperColumn.line-break-system-details
1282 #(list (cons 'alignment-extra-space (cdr (assoc 'system-stretch parameters)))
1283 (cons 'system-Y-extent (cdr (assoc 'system-Y-extent parameters))))
1287 #(define-music-function (parser location style heads music)
1288 (symbol? symbol-list-or-symbol? ly:music?)
1289 (_i "Set @var{heads} in @var{music} to @var{style}.")
1290 (style-note-heads heads style music))
1293 #(define-music-function (parser location tag music) (symbol-list-or-symbol? ly:music?)
1294 (_i "Tag the following @var{music} with @var{tag} and return the
1295 result, by adding the single symbol or symbol list @var{tag} to the
1296 @code{tags} property of @var{music}.")
1299 (ly:music-property music 'tags)
1300 ((if (symbol? tag) cons append)
1302 (ly:music-property music 'tags)))
1306 #(define-music-function (parser location music)
1308 (_i "Make any @code{\\override} in @var{music} replace an existing
1309 grob property value only temporarily, restoring the old value when a
1310 corresponding @code{\\revert} is executed. This is achieved by
1311 clearing the @samp{pop-first} property normally set on
1314 An @code{\\override}/@/@code{\\revert} sequence created by using
1315 @code{\\temporary} and @code{\\undo} on the same music containing
1316 overrides will cancel out perfectly or cause a@tie{}warning.
1318 Non-property-related music is ignored, warnings are generated for any
1319 property-changing music that isn't an @code{\\override}.")
1323 (and (or (music-is-of-type? m 'layout-instruction-event)
1324 (music-is-of-type? m 'context-specification)
1325 (music-is-of-type? m 'apply-context)
1326 (music-is-of-type? m 'time-signature-music))
1327 (case (ly:music-property m 'name)
1329 (if (ly:music-property m 'pop-first #f)
1330 (set! (ly:music-property m 'pop-first) '()))
1331 (if (ly:music-property m 'once #f)
1332 (set! (ly:music-property m 'once) '()))
1334 ((ContextSpeccedMusic)
1339 (ly:input-warning location (_ "Cannot make ~a revertible")
1340 (ly:music-property m 'name))
1347 #(define-music-function (parser location beat-structure fraction)
1348 ((number-list? '()) fraction?)
1349 (_i "Set @var{fraction} as time signature, with optional
1350 number list @var{beat-structure} before it.")
1351 (make-music 'TimeSignatureMusic
1352 'numerator (car fraction)
1353 'denominator (cdr fraction)
1354 'beat-structure beat-structure))
1357 #(define-music-function (parser location fraction music)
1358 (fraction? ly:music?)
1359 (_i "Scale @var{music} in time by @var{fraction}.")
1360 (make-music 'TimeScaledMusic
1361 'element (ly:music-compress music (ly:make-moment (car fraction) (cdr fraction)))
1362 'numerator (car fraction)
1363 'denominator (cdr fraction)))
1366 #(define-music-function
1367 (parser location from to music)
1368 (ly:pitch? ly:pitch? ly:music?)
1370 (_i "Transpose @var{music} from pitch @var{from} to pitch @var{to}.")
1371 (make-music 'TransposedMusic
1372 'element (ly:music-transpose music (ly:pitch-diff to from))))
1374 transposedCueDuring =
1375 #(define-music-function
1376 (parser location what dir pitch main-music)
1377 (string? ly:dir? ly:pitch? ly:music?)
1379 (_i "Insert notes from the part @var{what} into a voice called @code{cue},
1380 using the transposition defined by @var{pitch}. This happens
1381 simultaneously with @var{main-music}, which is usually a rest. The
1382 argument @var{dir} determines whether the cue notes should be notated
1383 as a first or second voice.")
1385 (make-music 'QuoteMusic
1387 'quoted-context-type 'CueVoice
1388 'quoted-context-id "cue"
1389 'quoted-music-name what
1390 'quoted-voice-direction dir
1391 ;; following is inverse of instrumentTransposition for
1392 ;; historical reasons
1393 'quoted-transposition pitch))
1396 #(define-music-function (parser location pitch) (ly:pitch?)
1397 (_i "Set instrument transposition")
1400 (make-property-set 'instrumentTransposition pitch)
1404 #(define-music-function (parser location ratio tuplet-span music)
1405 (fraction? (ly:duration? '()) ly:music?)
1406 (_i "Scale the given @var{music} to tuplets. @var{ratio} is a
1407 fraction that specifies how many notes are played in place of the
1408 nominal value: it will be @samp{3/2} for triplets, namely three notes
1409 being played in place of two. If the optional duration
1410 @var{tuplet-span} is specified, it is used instead of
1411 @code{tupletSpannerDuration} for grouping the tuplets.
1414 \\tuplet 3/2 4 @{ c8 c c c c c @}
1416 will result in two groups of three tuplets, each group lasting for a
1418 (make-music 'TimeScaledMusic
1419 'element (ly:music-compress
1421 (ly:make-moment (cdr ratio) (car ratio)))
1422 'numerator (cdr ratio)
1423 'denominator (car ratio)
1424 'duration tuplet-span))
1427 #(define-music-function (parser location tuplet-span)
1429 (_i "Set @code{tupletSpannerDuration}, the length into which
1430 @code{\\tuplet} without an explicit @samp{tuplet-span} argument of its
1431 own will group its tuplets, to the duration @var{tuplet-span}. To
1432 revert to the default of not subdividing the contents of a @code{\\tuplet}
1433 command without explicit @samp{tuplet-span}, use
1435 \\tupletSpan \\default
1439 #{ \set tupletSpannerDuration = #(ly:duration-length tuplet-span) #}
1440 #{ \unset tupletSpannerDuration #}))
1443 #(define-music-function (parser location prop value item)
1444 (symbol-list-or-symbol? scheme? symbol-list-or-music?)
1445 (_i "Add a tweak to the following @var{item}, usually music.
1446 Layout objects created by @var{item} get their property @var{prop}
1447 set to @var{value}. If @var{prop} has the form @samp{Grob.property}, like with
1449 \\tweak Accidental.color #red cis'
1451 an indirectly created grob (@samp{Accidental} is caused by
1452 @samp{NoteHead}) can be tweaked; otherwise only directly created grobs
1455 As a special case, @var{item} may be a symbol list specifying a grob
1456 path, in which case @code{\\once\\override} is called on it instead of
1457 creating tweaked music. This is mainly useful when using
1458 @code{\\tweak} as as a component for building other functions.
1460 @var{prop} can contain additional elements in which case a nested
1461 property (inside of an alist) is tweaked.")
1462 (if (ly:music? item)
1463 (let ((p (check-grob-path prop parser location
1468 (set! (ly:music-property item 'tweaks)
1469 (acons (cond ((pair? (cddr p)) p)
1471 (cons (car p) (cadr p)))
1474 (ly:music-property item 'tweaks))))
1476 ;; We could just throw this at \override and let it sort this
1477 ;; out on its own, but this way we should get better error
1479 (let ((a (check-grob-path item parser location
1480 #:default 'Bottom #:min 2 #:max 2))
1481 (b (check-grob-path prop parser location
1484 #{ \once\override #(append a b) = #value #}
1485 (make-music 'Music)))))
1488 #(define-music-function (parser location music)
1490 (_i "Convert @code{\\override} and @code{\\set} in @var{music} to
1491 @code{\\revert} and @code{\\unset}, respectively. Any reverts and
1492 unsets already in @var{music} cause a warning. Non-property-related music is ignored.")
1499 (lambda (m) (or (music-is-of-type? m 'layout-instruction-event)
1500 (music-is-of-type? m 'context-specification)
1501 (music-is-of-type? m 'apply-context)
1502 (music-is-of-type? m 'time-signature-music)))
1503 (lambda (m overrides)
1504 (case (ly:music-property m 'name)
1507 (make-music 'RevertProperty
1508 'symbol (ly:music-property m 'symbol)
1511 ((ly:music-property m 'grob-property #f) => list)
1513 (ly:music-property m 'grob-property-path))))
1517 (make-music 'PropertyUnset
1518 'symbol (ly:music-property m 'symbol))
1520 ((ContextSpeccedMusic)
1522 (make-music 'ContextSpeccedMusic
1523 'element (loop (ly:music-property m 'element))
1524 'context-type (ly:music-property m 'context-type))
1529 (ly:input-warning location (_ "Cannot revert ~a")
1530 (ly:music-property m 'name))
1536 ((null? lst) (make-music 'Music))
1537 ((null? (cdr lst)) (car lst))
1538 (else (make-sequential-music lst))))))
1541 #(define-music-function (parser location music) (ly:music?)
1542 (_i "Force any @code{\\repeat volta}, @code{\\repeat tremolo} or
1543 @code{\\repeat percent} commands in @var{music} to be interpreted
1544 as @code{\\repeat unfold}.")
1545 (unfold-repeats music))
1548 #(define-void-function (parser location arg) (scheme?)
1549 (_i "Accept a scheme argument, return a void expression.
1550 Use this if you want to have a scheme expression evaluated
1551 because of its side-effects, but its value ignored."))
1554 #(define-music-function (parser location sym val music)
1555 (symbol? scheme? ly:music?)
1556 (_i "Set @var{sym} to @var{val} in @var{music}.")
1558 (set! (ly:music-property music sym) val)