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 @strong{N.B. This Chapter is under heavy development at present.}
17 The purpose of LilyPond's design is to provide the finest output
18 quality as a default. Nevertheless, it may happen that you need to
19 change this default layout. The layout is controlled through a large
20 number of proverbial @q{knobs and switches.} This chapter does not
21 list each and every knob. Rather, it outlines what groups of controls
22 are available and explains how to lookup which knob to use for a
26 @cindex Internals Reference
28 The controls available for tuning are described in a separate
31 Internals Reference manual.
34 @ref{Top,Internals Reference,,lilypond-internals}.
37 lists all different variables, functions and options available in
38 LilyPond. It is written as a HTML document, which is available
39 @c leave the @uref as one long line.
40 @uref{http://@/lilypond@/.org/@/doc/@/stable/@/Documentation/@/user/@/lilypond@/-internals/,on@/-line},
41 but is also included with the LilyPond documentation package.
43 @c TODO The following is at variance to what actually follows. Fix -td
45 There are four areas where the default settings may be changed:
49 Automatic notation: changing the automatic creation of notation
50 elements. For example, changing the beaming rules.
53 Output: changing the appearance of individual
54 objects. For example, changing stem directions or the location of
58 Context: changing aspects of the translation from music events to
59 notation. For example, giving each staff a separate time signature.
62 Page layout: changing the appearance of the spacing, line
63 breaks, and page dimensions. These modifications are discussed
64 @c in @ref{notation}, and @ref{Spacing issues}.
67 Internally, LilyPond uses Scheme (a LISP dialect) to provide
68 infrastructure. Overriding layout decisions in effect accesses the
69 program internals, which requires Scheme input. Scheme elements are
70 introduced in a @code{.ly} file with the hash mark
71 @code{#}.@footnote{@rlearning{Scheme tutorial}, contains a short tutorial
72 on entering numbers, lists, strings, and symbols in Scheme.}
76 * Interpretation contexts::
77 * Explaining the Internals Reference::
78 * Modifying properties::
79 * Useful concepts and properties::
82 * Discussion of specific tweaks::
86 @node Interpretation contexts
87 @section Interpretation contexts
89 This section describes what contexts are, and how to modify them.
92 * Contexts explained::
94 * Modifying context plug-ins::
95 * Changing context default settings::
96 * Defining new contexts::
101 @node Contexts explained
102 @subsection Contexts explained
105 @c TODO Rethink and rewrite
107 >> > > - list of contexts: my *danger unmaintainable*
108 >> > > alarm just went off. I'm
110 I knew it would... And leaving out some of them is perfectly fine
112 I do think that a list like this, with the main contexts and a
114 description of what they do (perhaps also with a note about what
116 behavior is associated with each of them, but this may be
118 should be there, and then we could simply list the remaining ones
120 further explanation and with links to the IR.
123 @c TODO Improve layout, order and consistency of wording -td
125 @c TODO Add introduction which explains contexts in generality -td
127 Contexts are arranged heirarchically:
130 * Score - the master of all contexts::
131 * Top-level contexts - staff containers::
132 * Intermediate-level contexts - staves::
133 * Bottom-level contexts - voices::
136 @node Score - the master of all contexts
137 @unnumberedsubsubsec Score - the master of all contexts
139 This is the top level notation context. No other context can
140 contain a Score context. By default the Score context handles
141 the administration of time signatures and makes sure that items
142 such as clefs, time signatures, and key-signatures are aligned
145 A Score context is instantiated implicitly when a
146 @code{\score @{@dots{}@}} or @code{\layout @{@dots{}@}} block is
147 processed, or explicitly when a @code{\new Score} command is
150 @node Top-level contexts - staff containers
151 @unnumberedsubsubsec Top-level contexts - staff containers
153 @strong{@emph{StaffGroup}}
155 Groups staves while adding a bracket on the left side, grouping
156 the staves together. The bar lines of the contained staves are
157 connected vertically. StaffGroup only consists of a collection
158 of staves, with a bracket in front and spanning bar lines.
160 @strong{@emph{ChoirStaff}}
162 Identical to StaffGroup except that the bar lines of the contained
163 staves are not connected vertically.
165 @strong{@emph{GrandStaff}}
167 A group of staves, with a brace on the left side, grouping
168 the staves together. The bar lines of the contained staves are
169 connected vertically.
171 @strong{@emph{PianoStaff}}
173 TODO No longer correct? Check. -td
175 Just like GrandStaff but with a forced distance between the
176 staves, so cross staff beaming and slurring can be used.
178 @strong{@emph{InnerStaffGroup}}
182 @strong{@emph{InnerChoirStaff}}
186 @node Intermediate-level contexts - staves
187 @unnumberedsubsubsec Intermediate-level contexts - staves
189 @strong{@emph{Staff}}
191 Handles clefs, bar lines, keys, accidentals. It can contain
194 @strong{@emph{RhythmicStaff}}
196 Like Staff but for printing rhythms. Pitches are ignored;
197 the notes are printed on one line.
199 @strong{@emph{TabStaff}}
201 Context for generating tablature. By default lays the music
202 expression out as a guitar tablature, printed on six lines.
204 @strong{@emph{DrumStaff}}
206 Handles typesetting for percussion. Can contain DrumVoice
208 @strong{@emph{VaticanaStaff}}
210 Same as Staff, except that it is designed for typesetting
211 a piece in gregorian style.
213 @strong{@emph{MensuralStaff}}
215 Same as Staff, except that it is designed for typesetting
216 a piece in mensural style.
218 @node Bottom-level contexts - voices
219 @unnumberedsubsubsec Bottom-level contexts - voices
221 Voice-level contexts initialise certain properties and start
222 appropriate engravers. Being bottom-level contexts, they cannot
223 contain other contexts.
225 @strong{@emph{Voice}}
227 Corresponds to a voice on a staff. This context handles the
228 conversion of dynamic signs, stems, beams, super- and sub-scripts,
229 slurs, ties, and rests. You have to instantiate this explicitly
230 if you require multiple voices on the same staff.
232 @strong{@emph{VaticanaVoice}}
234 Same as Voice, except that it is designed for typesetting a piece
237 @strong{@emph{MensuralVoice}}
239 Same as Voice, with modifications for typesetting a piece in
242 @strong{@emph{Lyrics}}
244 Corresponds to a voice with lyrics. Handles the printing of a
245 single line of lyrics.
247 @strong{@emph{DrumVoice}}
249 The voice context used in a percussion staff.
251 @strong{@emph{FiguredBass}}
253 The context in which BassFigure objects are created from
254 input entered in @code{\figuremode} mode.
256 @strong{@emph{TabVoice}}
258 The voice context used within a TabStaff context. Usually left to
259 be created implicitly.
261 @strong{@emph{ChordNames}}
263 Typesets chord names.
265 ------------------------------
269 Then the following, which I don't know what to do with:
271 * GregorianTranscriptionVoice
272 * GregorianTranscriptionStaff
275 Engraves fretboards from chords. Not easy... Not
277 There is now some documentation on FretBoards in the NR, under
278 instrument-specific notation -- cds.
282 * CueVoice Not documented
284 Hard coded entry point for LilyPond. Cannot be tuned.
286 Silently discards all musical information given to this
290 @node Creating contexts
291 @subsection Creating contexts
293 @c TODO \new Score and \score
294 @c TODO more complete descriptions rather than learning style
296 For scores with only one voice and one staff, contexts are
297 created automatically. For more complex scores, it is necessary to
298 create them by hand. There are three commands that do this.
303 The easiest command is @code{\new}, and it also the quickest to type.
304 It is prepended to a music expression, for example
308 @cindex Context, creating
311 \new @var{type} @var{music expression}
315 where @var{type} is a context name (like @code{Staff} or
316 @code{Voice}). This command creates a new context, and starts
317 interpreting the @var{music expression} with that.
319 A practical application of @code{\new} is a score with many
320 staves. Each part that should be on its own staff, is preceded with
323 @lilypond[quote,verbatim,relative=2,ragged-right,fragment]
330 The @code{\new} command may also give a name to the context,
333 \new @var{type} = @var{id} @var{music}
335 However, this user specified name is only used if there is no other
336 context already earlier with the same name.
342 Like @code{\new}, the @code{\context} command also directs a music
343 expression to a context object, but gives the context an explicit name. The
347 \context @var{type} = @var{id} @var{music}
350 This form will search for an existing context of type @var{type}
351 called @var{id}. If that context does not exist yet, a new
352 context with the specified name is created. This is useful if
353 the context is referred to later on. For example, when
354 setting lyrics the melody is in a named context
357 \context Voice = "@b{tenor}" @var{music}
361 so the texts can be properly aligned to its notes,
364 \new Lyrics \lyricsto "@b{tenor}" @var{lyrics}
369 Another possible use of named contexts is funneling two different
370 music expressions into one context. In the following example,
371 articulations and notes are entered separately,
375 arts = @{ s4-. s4-> @}
378 They are combined by sending both to the same @code{Voice} context,
382 \new Staff \context Voice = "A" \music
383 \context Voice = "A" \arts
386 @lilypond[quote,ragged-right]
390 \new Staff \context Voice = "A" \music
391 \context Voice = "A" \arts
395 With this mechanism, it is possible to define an Urtext (original
396 edition), with the option to put several distinct articulations on the
399 @cindex creating contexts
402 The third command for creating contexts is
404 \context @var{type} @var{music}
409 This is similar to @code{\context} with @code{= @var{id}}, but matches
410 any context of type @var{type}, regardless of its given name.
412 This variant is used with music expressions that can be interpreted at
413 several levels. For example, the @code{\applyOutput} command (see
414 @ref{Running a function on all layout objects}). Without an explicit
415 @code{\context}, it is usually applied to @code{Voice}
418 \applyOutput #'@var{context} #@var{function} % apply to Voice
421 To have it interpreted at the @code{Score} or @code{Staff} level use
425 \applyOutput #'Score #@var{function}
426 \applyOutput #'Staff #@var{function}
432 @node Modifying context plug-ins
433 @subsection Modifying context plug-ins
435 @c TODO Should this be Modifying engravers or Modifying contexts?
437 Notation contexts (like @code{Score} and @code{Staff}) not only
439 they also contain plug-ins called @q{engravers} that create notation
440 elements. For example, the @code{Voice} context contains a
441 @code{Note_head_engraver} and the @code{Staff} context contains a
442 @code{Key_signature_engraver}.
444 For a full a description of each plug-in, see
446 @rinternals{Engravers and Performers}.
449 Internals Reference @expansion{} Translation @expansion{} Engravers.
451 Every context described in
453 @rinternals{Contexts}
456 Internals Reference @expansion{} Translation @expansion{} Context.
458 lists the engravers used for that context.
461 It can be useful to shuffle around these plug-ins. This is done by
462 starting a new context with @code{\new} or @code{\context}, and
468 \new @var{context} \with @{
481 where the @dots{} should be the name of an engraver. Here is a simple
482 example which removes @code{Time_signature_engraver} and
483 @code{Clef_engraver} from a @code{Staff} context,
485 @lilypond[quote,relative=1,verbatim,fragment]
491 \remove "Time_signature_engraver"
492 \remove "Clef_engraver"
499 In the second staff there are no time signature or clef symbols. This
500 is a rather crude method of making objects disappear since it will affect
501 the entire staff. This method also influences the spacing, which may or
502 may not be desirable. More sophisticated methods of blanking objects
503 are shown in @rlearning{Visibility and color of objects}.
505 The next example shows a practical application. Bar lines and time
506 signatures are normally synchronized across the score. This is done
507 by the @code{Timing_translator} and @code{Default_bar_line_engraver}.
508 This plug-in keeps an administration of time signature, location
509 within the measure, etc. By moving these engraver from @code{Score} to
510 @code{Staff} context, we can have a score where each staff has its own
513 @cindex polymetric scores
514 @cindex Time signatures, multiple
516 @lilypond[quote,relative=1,ragged-right,verbatim,fragment]
518 \remove "Timing_translator"
519 \remove "Default_bar_line_engraver"
522 \consists "Timing_translator"
523 \consists "Default_bar_line_engraver"
529 \consists "Timing_translator"
530 \consists "Default_bar_line_engraver"
539 @node Changing context default settings
540 @subsection Changing context default settings
542 The adjustments of the previous subsections (
543 @ref{The set command}, @ref{Modifying context plug-ins}, and
544 @ref{Overview of modifying properties}) can also be entered
545 separately from the music in the @code{\layout} block,
554 \override Stem #'thickness = #4.0
555 \remove "Time_signature_engraver"
560 The @code{\Staff} command brings in the existing definition of the
561 staff context so that it can be modified.
566 \override Stem #'thickness = #4.0
567 \remove "Time_signature_engraver"
571 affect all staves in the score. Other contexts can be modified
574 The @code{\set} keyword is optional within the @code{\layout} block, so
590 It is not possible to collect context changes in a variable and apply
591 them to a @code{\context} definition by referring to that variable.
593 The @code{\RemoveEmptyStaffContext} will overwrite your current
594 @code{\Staff} settings. If you wish to change the defaults for a
595 staff which uses @code{\RemoveEmptyStaffContext}, you must do so
596 after calling @code{\RemoveEmptyStaffContext}, ie
601 \RemoveEmptyStaffContext
603 \override Stem #'thickness = #4.0
608 TODO: add \with in here.
612 @node Defining new contexts
613 @subsection Defining new contexts
615 Specific contexts, like @code{Staff} and @code{Voice}, are made of
616 simple building blocks. It is possible to create new types of
617 contexts with different combinations of engraver plug-ins.
619 The next example shows how to build a different type of
620 @code{Voice} context from scratch. It will be similar to
621 @code{Voice}, but only prints centered slash note heads. It can be used
622 to indicate improvisation in jazz pieces,
624 @lilypond[quote,ragged-right]
627 \type "Engraver_group"
628 \consists "Note_heads_engraver"
629 \consists "Text_engraver"
630 \consists Pitch_squash_engraver
631 squashedPosition = #0
632 \override NoteHead #'style = #'slash
633 \override Stem #'transparent = ##t
637 \accepts "ImproVoice"
641 a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
642 c4 c^"undress" c_"while playing :)" c }
648 These settings are defined within a @code{\context} block inside a
649 @code{\layout} block,
659 In the following discussion, the example input shown should go in place
660 of the @dots{} in the previous fragment.
662 First it is necessary to define a name for the new context:
668 Since it is similar to the @code{Voice}, we want commands that work
669 on (existing) @code{Voice}s to remain working. This is achieved by
670 giving the new context an alias @code{Voice},
676 The context will print notes and instructive texts, so we need to add
677 the engravers which provide this functionality,
680 \consists Note_heads_engraver
681 \consists Text_engraver
684 but we only need this on the center line,
687 \consists Pitch_squash_engraver
688 squashedPosition = #0
691 The @rinternals{Pitch_squash_engraver} modifies note heads (created
692 by @rinternals{Note_heads_engraver}) and sets their vertical
693 position to the value of @code{squashedPosition}, in this case@tie{}@code{0},
696 The notes look like a slash, and have no stem,
699 \override NoteHead #'style = #'slash
700 \override Stem #'transparent = ##t
703 All these plug-ins have to cooperate, and this is achieved with a
704 special plug-in, which must be marked with the keyword @code{\type}.
705 This should always be @rinternals{Engraver_group},
708 \type "Engraver_group"
716 \type "Engraver_group"
717 \consists "Note_heads_engraver"
718 \consists "Text_engraver"
719 \consists Pitch_squash_engraver
720 squashedPosition = #0
721 \override NoteHead #'style = #'slash
722 \override Stem #'transparent = ##t
728 Contexts form hierarchies. We want to hang the @code{ImproVoice}
729 under @code{Staff}, just like normal @code{Voice}s. Therefore, we
730 modify the @code{Staff} definition with the @code{\accepts}
741 The opposite of @code{\accepts} is @code{\denies},
742 which is sometimes needed when reusing existing context definitions.
744 Putting both into a @code{\layout} block, like
754 \accepts "ImproVoice"
759 Then the output at the start of this subsection can be entered as
767 c c_"while playing :)"
774 @node Aligning contexts
775 @subsection Aligning contexts
777 New contexts may be aligned above or below existing contexts. This
778 could be useful in setting up a vocal staff (@rlearning{Vocal ensembles}) and
781 @c TODO Better example needed. Ref LM, and expand on it.
784 @findex alignAboveContext
785 @findex alignBelowContext
787 @lilypond[quote,ragged-right]
790 \relative c' \new Staff = "main" {
793 \new Staff \with {alignAboveContext=main} \ossia
801 @node Explaining the Internals Reference
802 @section Explaining the Internals Reference
806 * Navigating the program reference::
807 * Layout interfaces::
808 * Determining the grob property::
809 * Naming conventions::
812 @node Navigating the program reference
813 @subsection Navigating the program reference
815 @c TODO remove this (it's in the LM)
816 @c Replace with more factual directions
818 Suppose we want to move the fingering indication in the fragment
821 @lilypond[quote,fragment,relative=2,verbatim]
827 If you visit the documentation on fingering instructions (in
828 @ref{Fingering instructions}), you will notice:
833 Internals Reference: @rinternals{Fingering}.
838 @c outdated info; probably will delete.
840 This fragment points to two parts of the program reference: a page
841 on @code{FingerEvent} and one on @code{Fingering}.
843 The page on @code{FingerEvent} describes the properties of the music
844 expression for the input @code{-2}. The page contains many links
845 forward. For example, it says
848 Accepted by: @rinternals{Fingering_engraver},
852 That link brings us to the documentation for the Engraver, the
856 This engraver creates the following layout objects: @rinternals{Fingering}.
859 In other words, once the @code{FingerEvent}s are interpreted, the
860 @code{Fingering_engraver} plug-in will process them.
864 @c I can't figure out what this is supposed to mean. -gp
866 The @code{Fingering_engraver} is also listed to create
867 @rinternals{Fingering} objects,
869 @c old info? it doesn't make any sense to me with our current docs.
871 second bit of information listed under @b{See also} in the Notation
876 The programmer's reference is available as an HTML document. It is
877 highly recommended that you read it in HTML form, either online or
878 by downloading the HTML documentation. This section will be much more
879 difficult to understand if you are using the
883 Follow the link to @rinternals{Fingering}. At the top of the
887 Fingering objects are created by: @rinternals{Fingering_engraver} and
888 @rinternals{New_fingering_engraver}.
891 By following related links inside the program reference, we can follow the
892 flow of information within the program:
896 @item @rinternals{Fingering}:
897 @rinternals{Fingering} objects are created by:
898 @rinternals{Fingering_engraver}
900 @item @rinternals{Fingering_engraver}:
901 Music types accepted: @rinternals{fingering-event}
903 @item @rinternals{fingering-event}:
904 Music event type @code{fingering-event} is in Music expressions named
905 @rinternals{FingerEvent}
908 This path goes against the flow of information in the program: it
909 starts from the output, and ends at the input event. You could
910 also start at an input event, and read with the flow of
911 information, eventually ending up at the output object(s).
913 The program reference can also be browsed like a normal document. It
916 @rinternals{Music definitions},
919 @code{Music definitions}
921 on @rinternals{Translation}, and the @rinternals{Backend}. Every
922 chapter lists all the definitions used and all properties that may be
926 @node Layout interfaces
927 @subsection Layout interfaces
929 @cindex interface, layout
930 @cindex layout interface
933 The HTML page that we found in the previous section describes the
934 layout object called @rinternals{Fingering}. Such an object is a
935 symbol within the score. It has properties that store numbers (like
936 thicknesses and directions), but also pointers to related objects. A
937 layout object is also called a @emph{Grob}, which is short for Graphical
938 Object. For more details about Grobs, see @rinternals{grob-interface}.
940 The page for @code{Fingering} lists the definitions for the
941 @code{Fingering} object. For example, the page says
944 @code{padding} (dimension, in staff space):
950 which means that the number will be kept at a distance of at least 0.5
954 Each layout object may have several functions as a notational or
955 typographical element. For example, the Fingering object
956 has the following aspects
960 Its size is independent of the horizontal spacing, unlike slurs or beams.
963 It is a piece of text. Granted, it is usually a very short text.
966 That piece of text is typeset with a font, unlike slurs or beams.
969 Horizontally, the center of the symbol should be aligned to the
970 center of the note head.
973 Vertically, the symbol is placed next to the note and the staff.
976 The vertical position is also coordinated with other superscript
977 and subscript symbols.
980 Each of these aspects is captured in so-called @emph{interface}s,
981 which are listed on the @rinternals{Fingering} page at the bottom
984 This object supports the following interfaces:
985 @rinternals{item-interface},
986 @rinternals{self-alignment-interface},
987 @rinternals{side-position-interface}, @rinternals{text-interface},
988 @rinternals{text-script-interface}, @rinternals{font-interface},
989 @rinternals{finger-interface}, and @rinternals{grob-interface}.
992 Clicking any of the links will take you to the page of the respective
993 object interface. Each interface has a number of properties. Some of
994 them are not user-serviceable (@q{Internal properties}), but others
997 We have been talking of @emph{the} @code{Fingering} object, but actually it
998 does not amount to much. The initialization file (see
999 @rlearning{Other sources of information})
1000 @file{scm/@/define@/-grobs@/.scm} shows the soul of the @q{object},
1005 (avoid-slur . around)
1006 (slur-padding . 0.2)
1007 (staff-padding . 0.5)
1008 (self-alignment-X . 0)
1009 (self-alignment-Y . 0)
1010 (script-priority . 100)
1011 (stencil . ,ly:text-interface::print)
1012 (direction . ,ly:script-interface::calc-direction)
1013 (font-encoding . fetaNumber)
1014 (font-size . -5) ; don't overlap when next to heads.
1015 (meta . ((class . Item)
1016 (interfaces . (finger-interface
1018 text-script-interface
1020 side-position-interface
1021 self-alignment-interface
1022 item-interface))))))
1026 As you can see, the @code{Fingering} object is nothing more than a
1027 bunch of variable settings, and the webpage in the Internals Reference
1028 is directly generated from this definition.
1031 @node Determining the grob property
1032 @subsection Determining the grob property
1034 @c TODO remove this (it's in the LM)
1035 @c Replace with more factual directions
1037 Recall that we wanted to change the position of the @b{2} in
1039 @lilypond[quote,fragment,relative=2,verbatim]
1045 Since the @b{2} is vertically positioned next to its note, we have to
1046 meddle with the interface associated with this positioning. This is
1047 done using @code{side-position-interface}. The page for this interface
1051 @code{side-position-interface}
1053 Position a victim object (this one) next to other objects (the
1054 support). The property @code{direction} signifies where to put the
1055 victim object relative to the support (left or right, up or down?)
1060 Below this description, the variable @code{padding} is described as
1065 (dimension, in staff space)
1067 Add this much extra space between objects that are next to each other.
1071 By increasing the value of @code{padding}, we can move the
1072 fingering away from the note head. The following command inserts
1073 3 staff spaces of white
1074 between the note and the fingering:
1076 \once \override Voice.Fingering #'padding = #3
1079 Inserting this command before the Fingering object is created,
1080 i.e., before @code{c2}, yields the following result:
1082 @lilypond[quote,relative=2,fragment,verbatim]
1083 \once \override Voice.Fingering #'padding = #3
1090 In this case, the context for this tweak is @code{Voice}. This
1091 fact can also be deduced from the program reference, for the page for
1092 the @rinternals{Fingering_engraver} plug-in says
1095 Fingering_engraver is part of contexts: @dots{} @rinternals{Voice}
1099 @node Naming conventions
1100 @subsection Naming conventions
1102 Another thing that is needed, is an overview of the various naming
1105 scheme functions: lowercase-with-hyphens (incl. one-word
1107 scheme functions: ly:plus-scheme-style
1108 music events, music classes and music properties:
1110 Grob interfaces: scheme-style
1111 backend properties: scheme-style (but X and Y!)
1112 contexts (and MusicExpressions and grobs): Capitalized or
1114 context properties: lowercaseFollowedByCamelCase
1116 Capitalized_followed_by_lowercase_and_with_underscores
1118 Which of these are conventions and which are rules?
1119 Which are rules of the underlying language, and which are
1123 @node Modifying properties
1124 @section Modifying properties
1127 * Overview of modifying properties::
1129 * The override command::
1130 * set versus override::
1131 * The tweak command::
1135 @node Overview of modifying properties
1136 @subsection Overview of modifying properties
1138 Each context is responsible for creating certain types of graphical
1139 objects. The settings used for printing these objects are also stored by
1140 context. By changing these settings, the appearance of objects can be
1143 The syntax for this is
1146 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1149 Here @var{name} is the name of a graphical object, like
1150 @code{Stem} or @code{NoteHead}, and @var{property} is an internal
1151 variable of the formatting system (@q{grob property} or @q{layout
1152 property}). The latter is a symbol, so it must be quoted. The
1153 subsection @ref{Modifying properties}, explains what to fill in
1154 for @var{name}, @var{property}, and @var{value}. Here we only
1155 discuss the functionality of this command.
1160 \override Staff.Stem #'thickness = #4.0
1164 makes stems thicker (the default is 1.3, with staff line thickness as a
1165 unit). Since the command specifies @code{Staff} as context, it only
1166 applies to the current staff. Other staves will keep their normal
1167 appearance. Here we see the command in action:
1169 @lilypond[quote,verbatim,relative=2,fragment]
1171 \override Staff.Stem #'thickness = #4.0
1177 The @code{\override} command changes the definition of the @code{Stem}
1178 within the current @code{Staff}. After the command is interpreted
1179 all stems are thickened.
1181 Analogous to @code{\set}, the @var{context} argument may be left out,
1182 causing the default context @code{Voice} to be used. Adding
1183 @code{\once} applies the change during one timestep only.
1185 @lilypond[quote,fragment,verbatim,relative=2]
1187 \once \override Stem #'thickness = #4.0
1192 The @code{\override} must be done before the object is
1193 started. Therefore, when altering @emph{Spanner} objects such as slurs
1194 or beams, the @code{\override} command must be executed at the moment
1195 when the object is created. In this example,
1197 @lilypond[quote,fragment,verbatim,relative=2]
1198 \override Slur #'thickness = #3.0
1200 \override Beam #'thickness = #0.6
1205 the slur is fatter but the beam is not. This is because the command for
1206 @code{Beam} comes after the Beam is started, so it has no effect.
1208 Analogous to @code{\unset}, the @code{\revert} command for a context
1209 undoes an @code{\override} command; like with @code{\unset}, it only
1210 affects settings that were made in the same context. In other words, the
1211 @code{\revert} in the next example does not do anything.
1214 \override Voice.Stem #'thickness = #4.0
1215 \revert Staff.Stem #'thickness
1218 Some tweakable options are called @q{subproperties} and reside inside
1219 properties. To tweak those, use commands of the form
1221 @c leave this as a long long
1223 \override @var{context}.@var{name} #'@var{property} #'@var{subproperty} = #@var{value}
1230 \override Stem #'details #'beamed-lengths = #'(4 4 3)
1236 Internals: @rinternals{OverrideProperty}, @rinternals{RevertProperty},
1237 @rinternals{PropertySet}, @rinternals{Backend}, and
1238 @rinternals{All layout objects}.
1243 The back-end is not very strict in type-checking object properties.
1244 Cyclic references in Scheme values for properties can cause hangs
1245 or crashes, or both.
1249 @node The set command
1250 @subsection The @code{\set} command
1254 @cindex changing properties
1256 Each context can have different @emph{properties}, variables contained
1257 in that context. They can be changed during the interpretation step.
1258 This is achieved by inserting the @code{\set} command in the music,
1261 \set @var{context}.@var{prop} = #@var{value}
1265 @lilypond[quote,verbatim,relative=2,fragment]
1267 \set Score.skipBars = ##t
1271 This command skips measures that have no notes. The result is that
1272 multi-rests are condensed. The value assigned is a Scheme object. In
1273 this case, it is @code{#t}, the boolean True value.
1275 If the @var{context} argument is left out, then the current bottom-most
1276 context (typically @code{ChordNames}, @code{Voice}, or
1277 @code{Lyrics}) is used. In this example,
1279 @lilypond[quote,verbatim,relative=2,fragment]
1281 \set autoBeaming = ##f
1286 the @var{context} argument to @code{\set} is left out, so automatic
1287 beaming is switched off in the current @rinternals{Voice}. Note that
1288 the bottom-most context does not always contain the property that you
1289 wish to change -- for example, attempting to set the @code{skipBars}
1290 property (of the bottom-most context, in this case @code{Voice}) will
1293 @lilypond[quote,verbatim,relative=2,fragment]
1299 Contexts are hierarchical, so if a bigger context was specified, for
1300 example @code{Staff}, then the change would also apply to all
1301 @code{Voice}s in the current stave. The change is applied
1302 @q{on-the-fly}, during the music, so that the setting only affects the
1303 second group of eighth notes.
1307 There is also an @code{\unset} command,
1309 \unset @var{context}.@var{prop}
1313 which removes the definition of @var{prop}. This command removes
1314 the definition only if it is set in @var{context}, so
1317 \set Staff.autoBeaming = ##f
1321 introduces a property setting at @code{Staff} level. The setting also
1322 applies to the current @code{Voice}. However,
1325 \unset Voice.autoBeaming
1329 does not have any effect. To cancel this setting, the @code{\unset}
1330 must be specified on the same level as the original @code{\set}. In
1331 other words, undoing the effect of @code{Staff.autoBeaming = ##f}
1334 \unset Staff.autoBeaming
1337 Like @code{\set}, the @var{context} argument does not have to be
1338 specified for a bottom context, so the two statements
1341 \set Voice.autoBeaming = ##t
1342 \set autoBeaming = ##t
1350 Settings that should only apply to a single time-step can be entered
1351 with @code{\once}, for example in
1353 @lilypond[quote,verbatim,relative=2,fragment]
1355 \once \set fontSize = #4.7
1360 the property @code{fontSize} is unset automatically after the second
1363 A full description of all available context properties is in the
1364 program reference, see
1366 @rinternals{Tunable context properties}.
1369 Translation @expansion{} Tunable context properties.
1374 @node The override command
1375 @subsection The @code{\override} command
1377 Commands which change output generally look like
1380 \override Voice.Stem #'thickness = #3.0
1384 To construct this tweak we must determine these bits of information:
1387 @item the context: here @code{Voice}.
1388 @item the layout object: here @code{Stem}.
1389 @item the layout property: here @code{thickness}.
1390 @item a sensible value: here @code{3.0}.
1393 Some tweakable options are called @q{subproperties} and reside inside
1394 properties. To tweak those, use commands in the form
1397 \override Stem #'details #'beamed-lengths = #'(4 4 3)
1400 @cindex internal documentation
1401 @cindex finding graphical objects
1402 @cindex graphical object descriptions
1405 @cindex internal documentation
1407 For many properties, regardless of the data type of the property, setting the
1408 property to false ( @code{##f} ) will result in turning it off, causing
1409 LilyPond to ignore that property entirely. This is particularly useful for
1410 turning off grob properties which may otherwise be causing problems.
1412 We demonstrate how to glean this information from the notation manual
1413 and the program reference.
1416 @node set versus override
1417 @subsection @code{\set} vs. @code{\override}
1419 We have seen two methods of changing properties: @code{\set} and
1420 @code{\override}. There are actually two different kinds of
1423 Contexts can have properties, which are usually named in
1424 @code{studlyCaps}. They mostly control the translation from
1425 music to notation, eg. @code{localKeySignature} (for determining
1426 whether to print accidentals), @code{measurePosition} (for
1427 determining when to print a bar line). Context properties can
1428 change value over time while interpreting a piece of music;
1429 @code{measurePosition} is an obvious example of
1430 this. Context properties are modified with @code{\set}.
1432 There is a special type of context property: the element
1433 description. These properties are named in @code{StudlyCaps}
1434 (starting with capital letters). They contain the
1435 @q{default settings} for said graphical object as an
1436 association list. See @file{scm/@/define@/-grobs@/.scm}
1437 to see what kind of settings there are. Element descriptions
1438 may be modified with @code{\override}.
1440 @code{\override} is actually a shorthand;
1443 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1447 is more or less equivalent to
1449 @c leave this long line -gp
1451 \set @var{context}.@var{name} #'@var{property} = #(cons (cons '@var{property} @var{value}) <previous value of @var{context})
1454 The value of @code{context} (the alist) is used to initialize
1455 the properties of individual grobs. Grobs also have
1456 properties, named in Scheme style, with
1457 @code{dashed-words}. The values of grob properties change
1458 during the formatting process: formatting basically amounts
1459 to computing properties using callback functions.
1461 @code{fontSize} is a special property: it is equivalent to
1462 entering @code{\override ... #'font-size} for all pertinent
1463 objects. Since this is a common change, the special
1464 property (modified with @code{\set}) was created.
1467 @node The tweak command
1468 @subsection The @code{\tweak} command
1470 TODO: can't use \tweak in a variable
1474 In some cases, it is possible to take a short-cut for tuning graphical
1475 objects. For objects that result directly from a piece of the input,
1476 you can use the @code{\tweak} function, for example
1478 @lilypond[relative=2,fragment,verbatim,ragged-right]
1481 \tweak #'color #red d
1483 \tweak #'duration-log #1 a
1484 >4-\tweak #'padding #10 -.
1487 As you can see, properties are set in the objects directly,
1488 without mentioning the grob name or context where this should be
1491 This technique only works for objects that are directly connected to
1492 an @rinternals{Event} from the input, for example
1495 @item note heads, caused by chord-pitch (i.e., notes inside a chord)
1496 @item articulation signs, caused by articulation instructions
1499 It notably does not work for stems and accidentals (these are caused
1500 by note heads, not by music events) or clefs (these are not caused by
1501 music inputs, but rather by the change of a property value).
1503 There are very few objects which are @emph{directly} connected to
1504 output. A normal note (like @code{c4}) is not directly connected
1508 \tweak #'color #red c4
1512 does not change color. See @ref{Displaying music expressions}, for
1516 @node Useful concepts and properties
1517 @section Useful concepts and properties
1522 * Direction and placement::
1523 * Distances and measurements::
1528 @subsection Input modes
1530 The way in which the notation contained within an input file is
1531 interpreted is determined by the current input mode.
1535 This is activated with the @code{\chordmode} command, and causes
1536 input to be interpreted with the syntax of chord notation, see
1537 @ref{Chord notation}. Chords are rendered as notes on a staff.
1539 Chord mode is also activated with the @code{\chords} command.
1540 This also creates a new @code{ChordNames} context and
1541 causes the following input to be interpreted with the syntax of
1542 chord notation and rendered as chord names in the @code{ChordNames}
1543 context, see @ref{Printing chord names}.
1547 This is activated with the @code{\drummode} command, and causes
1548 input to be interpreted with the syntax of drum notation, see
1549 @ref{Basic percussion notation}.
1551 Drum mode is also activated with the @code{\drums} command.
1552 This also creates a new @code{DrumStaff} context and causes the
1553 following input to be interpreted with the syntax of drum notation
1554 and rendered as drum symbols on a drum staff, see @ref{Basic
1555 percussion notation}.
1557 @strong{Figure mode}
1559 This is activated with the @code{\figuremode} command, and causes
1560 input to be interpreted with the syntax of figured bass, see
1561 @ref{Entering figured bass}.
1563 Figure mode is also activated with the @code{\figures} command.
1564 This also creates a new @code{FiguredBass} context and causes the
1565 following input to be interpreted with the figured bass syntax
1566 and rendered as figured bass symbols in the @code{FiguredBass}
1567 context, see @ref{Introduction to figured bass}.
1569 @strong{Fret and tab modes}
1571 There are no special input modes for entering fret and tab symbols.
1573 To create tab diagrams, enter notes or chords in note mode and
1574 render them in a @code{TabStaff} context, see
1575 @ref{Default tablatures}.
1577 To create fret diagrams above a staff, you have two choices.
1578 You can either use the @code{FretBoards} context (see
1579 @ref{Automatic fret diagrams} or you can enter them as a markup
1580 above the notes using the @code{\fret-diagram} command (see
1581 @ref{Fret diagram markups}).
1583 @strong{Lyrics mode}
1585 This is activated with the @code{\lyricmode} command, and causes
1586 input to be interpreted as lyric syllables with optional durations
1587 and associated lyric modifiers, see @ref{Vocal music}.
1589 Lyric mode is also activated with the @code{\addlyrics} command.
1590 This also creates a new @code{Lyrics} context and an implicit
1591 @code{\lyricsto} command which associates the following lyrics
1592 with the preceding music.
1594 @strong{Markup mode}
1596 This is activated with the @code{\markup} command, and causes
1597 input to be interpreted with the syntax of markup, see
1598 @ref{Text markup commands}.
1600 @c silly work-around for texinfo broken-ness
1601 @c (@strong{Note...} causes a spurious cross-reference in Info)
1604 This is the default mode or it may be activated with the
1605 @code{\notemode} command. Input is interpreted as pitches,
1606 durations, markup, etc and typeset as musical notation on a staff.
1608 It is not normally necessary to specify note mode explicitly, but
1609 it may be useful to do so in certain situations, for example if you
1610 are in lyric mode, chord mode or any other mode and want to insert
1611 something that only can be done with note mode syntax.
1613 For example, to indicate dynamic markings for the verses of a
1614 choral pieces it is necessary to enter note mode to interpret
1617 @lilypond[verbatim,relative=2,quote]
1620 \notemode{\set stanza = \markup{ \dynamic f 1. } }
1624 \notemode{\set stanza = \markup{ \dynamic p 2. } }
1631 @node Direction and placement
1632 @subsection Direction and placement
1634 In typesetting music the direction and placement of many items is
1635 a matter of choice. For example, the stems of notes can
1636 be directed up or down; lyrics, dynamics, and other expressive
1637 marks may be placed above or below the staff; text may be aligned
1638 left, right or center; etc. Most of these choices may be left to
1639 be determined automatically by LilyPond, but in some cases it may
1640 be desirable to force a particular direction or placement.
1642 @strong{Default actions}
1644 By default some directions are always up or always down (e.g.
1645 dynamics or fermata), while other things can alternate between
1646 up or down based on the stem direction (like slurs or accents).
1648 @c TODO Add table showing these
1650 @strong{Context layout}
1652 Contexts are positioned in a system from top to bottom in the
1653 order in which they are encountered. Note, however, that a
1654 context will be created implicitly if a command is encountered
1655 when there is no suitable context available to contain it.
1657 @c TODO Add example ?
1659 The default order in which contexts are laid out can be changed,
1660 see @ref{Aligning contexts}
1662 @strong{Articulation direction indicators}
1664 When adding articulations to notes the direction indicator,
1665 @code{^} (meaning @qq{up}), @code{_} (meaning @qq{down}) or
1666 @code{-} (meaning @qq{use default direction}), can usually be
1667 omitted, in which case @code{-} is assumed. But a direction
1668 indicator is @strong{always} required before
1671 @item @code{\tweak} commands
1672 @item @code{\markup} commands
1673 @item @code{\tag} commands
1674 @item string markups, e.g. -"string"
1675 @item fingering instructions, e.g. @code{-1}
1676 @item articulation shortcuts, e.g. @code{-.}, @code{->}, @code{--}
1679 @strong{The direction property}
1681 The position or direction of many layout objects is controlled
1682 by the @code{direction} property.
1684 The value of the @code{direction} property may be
1685 set to @code{1}, meaning @qq{up} or @qq{above}, or to @code{-1},
1686 meaning @qq{down} or @qq{below}. The symbols @code{UP} and
1687 @code{DOWN} may be used instead of @code{1} and @code{-1}
1688 respectively. The default direction may be specified by setting
1689 @code{direction} to @code{0} or @code{CENTER}. Alternatively,
1690 in many cases predefined commands
1691 exist to specify the direction. These are all of the form
1694 @code{\xxxUp}, @code{xxxDown}, @code{xxxNeutral}
1697 where @code{xxxNeutral} means @qq{use the default direction}.
1698 See @rlearning{Within-staff objects}.
1700 In a few cases, arpeggio being the only common example, the value
1701 of the @code{direction} property specifies whether the object
1702 is to be placed to the right or left of the parent object. In
1703 this case @code{-1} or @code{LEFT} means @qq{to the left} and
1704 @code{1} or @code{RIGHT} means @qq{to the right}. @code{0}
1705 or @code{CENTER} means @qq{use the default} direction, as before.
1708 These all have side-axis set to #X
1709 AmbitusAccidental - direction has no effect
1711 StanzaNumber - not tried
1712 TrillPitchAccidental - not tried
1713 TrillPitchGroup - not tried
1718 @node Distances and measurements
1719 @subsection Distances and measurements
1721 DISCUSS after working on other sections.
1723 TODO: staff spaces. Maybe move into tweaks?
1727 @subsection Spanners
1729 Many objects of musical notation extend over several notes or even
1730 several bars. Examples are crescendi, trills, tuplet brackets, and
1731 volta repeat brackets. Such objects are called @qq{spanners}, and
1732 have special properties to control their appearance and behaviour.
1733 Some of these properties are common to all spanners; others are
1734 restricted to a sub-set of the spanners.
1736 @node Common properties
1737 @section Common properties
1740 * Controlling visibility of objects::
1742 * Rotating objects::
1743 * Aligning objects::
1746 @c TODO Add new subsection Shapes of objects
1747 @c which would include Slur shapes
1748 @c with a Known issue: can't modify shapes with 'control-points if there are
1749 @c more than one at the same musical moment
1751 @node Controlling visibility of objects
1752 @subsection Controlling visibility of objects
1754 @cindex objects, visibility of
1755 @cindex grobs, visibility of
1756 @cindex visibility of objects
1758 There are four main ways in which the visibility of layout objects
1759 can be controlled: their stencil can be removed, they can be made
1760 transparent, they can be colored white, or their
1761 @code{break-visibility} property can be overridden. The first
1762 three apply to all layout objects; the last to just a few -- the
1763 @emph{breakable} objects. The Learning Manual introduces these
1764 four techniques, see @rlearning{Visibility and color of objects}.
1766 There are also a few other techniques which are specific to
1767 certain layout objects. These are covered under Special
1771 * Removing the stencil::
1772 * Making objects transparent::
1773 * Painting objects white::
1774 * Using break-visibility::
1775 * Special considerations::
1779 @node Removing the stencil
1780 @unnumberedsubsubsec Removing the stencil
1782 @cindex stencil, removing
1784 Every layout object has a stencil property. By default this is set
1785 to the specific function which draws that object. If this property
1786 is overridden to @code{#f} no function will be called and the object
1787 will not be drawn. The default action can be recovered with
1790 @lilypond[quote,verbatim,relative=1]
1792 \override Score.BarLine #'stencil = ##f
1794 \revert Score.BarLine #'stencil
1798 @node Making objects transparent
1799 @unnumberedsubsubsec Making objects transparent
1801 @cindex transparent, making objects
1803 Every layout object has a transparent property which by default is
1804 set to @code{#f}. If set to @code{#t} the object still occupies
1805 space but is made invisible.
1807 @lilypond[quote,verbatim,relative=2]
1809 \once \override NoteHead #'transparent = ##t
1813 @node Painting objects white
1814 @unnumberedsubsubsec Painting objects white
1816 @cindex objects, coloring
1817 @cindex coloring objects
1819 @cindex printing order
1820 @cindex overwriting objects
1821 @cindex objects, overwriting
1822 @cindex grobs, overwriting
1824 Every layout object has a color property which by default is set
1825 to @code{black}. If this is overridden to @code{white} the object
1826 will be indistinguishable from the white background. However,
1827 if the object crosses other objects the color of the crossing
1828 points will be determined by the order in which they are drawn,
1829 and this may leave a ghostly image of the white object, as shown
1832 @lilypond[quote,verbatim,relative=2]
1833 \override Staff.Clef #'color = #white
1837 This may be avoided by changing the order of printing the objects.
1838 All layout objects have a @code{layer} property which should be set
1839 to an integer. Objects with the lowest value of @code{layer} are
1840 drawn first, then objects with progressively higher values are drawn,
1841 so objects with higher values overwrite objects with lower values.
1842 By default most objects are assigned a @code{layer} value of
1843 @code{1}, although a few objects, including @code{StaffSymbol} and
1844 @code{BarLine}, are assigned a value of @code{0}. The order of
1845 printing objects with the same value of @code{layer} is indeterminate.
1847 In the example above the white clef, with a default @code{layer}
1848 value of @code{1}, is drawn after the staff lines (default
1849 @code{layer} value @code{0}), so overwriting them. To change this,
1850 the @code{Clef} object must be given in a lower value of
1851 @code{layer}, say @code{-1}, so that it is drawn earlier:
1853 @lilypond[quote,verbatim,relative=2]
1854 \override Staff.Clef #'color = #white
1855 \override Staff.Clef #'layer = #-1
1859 @node Using break-visibility
1860 @unnumberedsubsubsec Using break-visibility
1862 @c TODO Add making other objects breakable
1864 @cindex break-visibility
1866 Most layout objects are printed only once, but some like
1867 bar lines, clefs, time signatures and key signatures, may need
1868 to be printed twice when a line break occurs -- once at the end
1869 of the line and again at the start of the next line. Such
1870 objects are called @emph{breakable}, and have a property, the
1871 @code{break-visibility} property to control their visibility
1872 at the three positions in which they may appear -- at the
1873 start of a line, within a line if they are changed, and at the
1874 end of a line if a change takes place there.
1876 For example, the time signature
1877 by default will be printed at the start of the first line, but
1878 nowhere else unless it changes, when it will be printed at the
1879 point at which the change occurs. If this change occurs at the
1880 end of a line the new time signature will be printed at the start
1881 of the next line and a cautionary time signature will be printed
1882 at the end of the previous line as well.
1884 This behaviour is controlled by the @code{break-visibility}
1885 property, which is explained in
1886 @c Leave this ref on a newline - formats incorrectly otherwise -td
1887 @rlearning{Visibility and color of objects}. This property takes
1888 a vector of three booleans which, in order, determine whether the
1889 object is printed at the end of, within the body of, or at the
1890 beginning of a line. Or to be more precise, before a line break,
1891 where there is no line break, or after a line break.
1893 Alternatively, seven of the eight combinations may be specified
1894 by pre-defined functions, defined in @file{scm/output-lib.scm},
1895 where the last three columns indicate whether the layout objects
1896 will be visible in the positions shown at the head of the columns:
1898 @multitable @columnfractions .40 .15 .1 .1 .1
1899 @c TODO check these more carefully
1900 @headitem Function @tab Vector @tab Before @tab At no @tab After
1901 @headitem form @tab form @tab break @tab break @tab break
1903 @item @code{all-invisible} @tab @code{'#(#f #f #f)} @ @ @tab no @tab no @tab no
1904 @item @code{begin-of-line-visible} @tab @code{'#(#f #f #t)} @tab no @tab no @tab yes
1905 @item @code{end-of-line-visible} @tab @code{'#(#t #f #f)} @tab yes @tab no @tab no
1906 @item @code{all-visible} @tab @code{'#(#t #t #t)} @tab yes @tab yes @tab yes
1907 @c The center-visible function is not defined
1908 @c @item @code{center-visible} @tab @code{'#(#f #t #f)} @tab no @tab yes @tab no
1909 @item @code{begin-of-line-invisible} @tab @code{'#(#t #t #f)} @tab yes @tab yes @tab no
1910 @item @code{end-of-line-invisible} @tab @code{'#(#f #t #t)} @tab no @tab yes @tab yes
1911 @item @code{center-invisible} @tab @code{'#(#t #f #t)} @tab yes @tab no @tab yes
1914 The @code{center-visible} function is not pre-defined.
1916 The default settings of @code{break-visibility} depend on the
1917 layout object. The following table shows all the layout objects
1918 of interest which are affected by @code{break-visibility} and the
1919 default setting of this property:
1921 @multitable @columnfractions .3 .3 .4
1923 @headitem Layout object @tab Usual context @tab Default setting
1925 @c omit Ambitus as it appears not to be affected by break-visibility -td
1926 @c @item @code{Ambitus} @tab as specified @tab @code{begin-of-line-visible}
1927 @item @code{BarLine} @tab @code{Score} @tab calculated
1928 @item @code{BarNumber} @tab @code{Score} @tab @code{begin-of-line-visible}
1929 @c omit the following item until it can be explained -td
1930 @c @item @code{BreakAlignGroup} @tab @code{Score} @tab calculated
1931 @item @code{BreathingSign} @tab @code{Voice} @tab @code{begin-of-line-invisible}
1932 @item @code{Clef} @tab @code{Staff} @tab @code{begin-of-line-visible}
1933 @item @code{Custos} @tab @code{Staff} @tab @code{end-of-line-visible}
1934 @item @code{DoublePercentRepeat} @tab @code{Voice} @tab @code{begin-of-line-invisible}
1935 @c omit KeyCancellation until it can be explained -td
1936 @c @item @code{KeyCancellation} @tab ?? @tab @code{begin-of-line-invisible}
1937 @item @code{KeySignature} @tab @code{Staff} @tab @code{begin-of-line-visible}
1938 @c omit LeftEdge until it can be explained -td
1939 @c @item @code{LeftEdge} @tab @code{Score} @tab @code{center-invisible}
1940 @item @code{OctavateEight} @tab @code{Staff} @tab @code{begin-of-line-visible}
1941 @item @code{RehearsalMark} @tab @code{Score} @tab @code{end-of-line-invisible}
1942 @item @code{TimeSignature} @tab @code{Staff} @tab @code{all-visible}
1946 The example below shows the use of the vector form to control the
1947 visibility of barlines:
1949 @lilypond[quote,verbatim,relative=1,ragged-right]
1952 % Remove bar line at the end of the current line
1953 \once \override Score.BarLine #'break-visibility = #'#(#f #t #t)
1959 Although all three components of the vector used to override
1960 @code{break-visibility} must be present, not all of them are
1961 effective with every layout object, and some combinations may
1962 even give errors. The following limitations apply:
1965 @item Bar lines cannot be printed at start of line.
1966 @item A bar number cannot be printed at the start of the first
1967 line unless it is set to be different from 1.
1968 @item Clef -- see below
1969 @item Double percent repeats are either all printed or all
1970 suppressed. Use begin-of line-invisible to print and
1971 all-invisible to suppress.
1972 @item Key signature -- see below
1973 @item OctavateEight -- see below
1976 @node Special considerations
1977 @unnumberedsubsubsec Special considerations
1979 @strong{@emph{Visibility following explicit changes}}
1981 @cindex key signature, visibility following explicit change
1982 @cindex explicitKeySignatureVisibility
1983 @cindex clef, visibility following explicit change
1984 @cindex explicitClefVisibility
1986 The @code{break-visibility} property controls the visibility of
1987 key signatures and changes of clef only at the start of lines,
1988 i.e. after a break. It has no effect on the visibility of the
1989 key signature or clef following an explicit key change or an
1990 explicit clef change within or at the end of a line. In the
1991 following example the key signature following the explicit change
1992 to B-flat major is still visible, even though @code{all-invisible}
1995 @lilypond[quote,verbatim,relative=1,ragged-right]
1998 % Try to remove all key signatures
1999 \override Staff.KeySignature #'break-visibility = #all-invisible
2007 The visibility of such explicit key signature and clef changes is
2008 controlled by the @code{explicitKeySignatureVisibility} and
2009 @code{explicitClefVisibility} properties. These are the equivalent
2010 of the @code{break-visibility} property and both take a vector of
2011 three booleans or the predefined functions listed above, exactly like
2012 @code{break-visibility}. Both are properties of the Staff context,
2013 not the layout objects themselves, and so they are set using the
2014 @code{\set} command. Both are set by default to @code{all-visible}.
2015 These properties control only the visibility of key signatures and
2016 clefs resulting from explicit changes and do not affect key
2017 signatures and clefs at the beginning of lines;
2018 @code{break-visibility} must still be overridden in the appropriate
2019 object to remove these.
2021 @lilypond[quote,verbatim,relative=1,ragged-right]
2024 \set Staff.explicitKeySignatureVisibility = #all-invisible
2025 \override Staff.KeySignature #'break-visibility = #all-invisible
2032 @strong{@emph{Visibility of cautionary accidentals}}
2034 To remove the cautionary accidentals printed at an explicit key
2035 change, set the Staff context property @code{printKeyCancellation}
2038 @lilypond[quote,verbatim,relative=1,ragged-right]
2041 \set Staff.explicitKeySignatureVisibility = #all-invisible
2042 \set Staff.printKeyCancellation = ##f
2043 \override Staff.KeySignature #'break-visibility = #all-invisible
2050 With these overrides only the accidentals before the notes remain
2051 to indicate the change of key.
2053 @c TODO Add visibility of cautionary accidentals before notes
2055 @strong{@emph{Automatic bars}}
2057 @cindex automaticBars
2058 @cindex bar lines, suppressing
2060 As a special case, the printing of bar lines can also be turned off
2061 by setting the @code{automaticBars} property in the Score context.
2062 If set to @code{#f}, bar lines will not be printed automatically;
2063 they must be explicitly created with a @code{\bar} command. Unlike
2064 the @code{\cadenzaOn} predefined command, measures are still counted.
2065 Bar generation will resume according to that count if this property
2066 is later set to @code{#t}. When set to @code{#f}, line breaks can
2067 occur only at explicit @code{\bar} commands.
2071 @strong{@emph{Octavated clefs}}
2073 @cindex octavated clefs, visibility of
2074 @cindex visibility of octavated clefs
2075 @cindex clefs, visibility of octavation
2077 The small octavation symbol on octavated clefs is produced by the
2078 @code{OctavateEight} layout object. Its visibility is controlled
2079 independently from that of the @code{Clef} object, so it is
2080 necessary to apply any required @code{break-visibility} overrides
2081 to both the @code{Clef} and the @code{OctavateEight} layout objects
2082 to fully suppress such clef symbols at the start of each line.
2084 For explicit clef changes, the @code{explicitClefVisibility}
2085 property controls both the clef symbol and any octavation symbol
2091 @rlearning{Visibility and color of objects}
2095 @subsection Line styles
2097 @c TODO: split the following explanations between expressive marks and
2098 @c text-related stuff. Perhaps create a new subsection named
2099 @c "Spanner limits", "Spanner boundaries"? -vv
2101 Some performance indications, e.g., @i{rallentando} and
2102 @i{accelerando} and @i{trills} are written as text and are
2103 extended over many measures with lines, sometimes dotted or wavy.
2105 These all use the same routines as the glissando for drawing the
2106 texts and the lines, and tuning their behavior is therefore also
2107 done in the same way. It is done with a spanner, and the routine
2108 responsible for drawing the spanners is
2109 @code{ly:line-interface::print}. This routine determines the
2110 exact location of the two @i{span points} and draws a line in
2111 between, in the style requested.
2113 Here is an example of the different line styles available, and how
2116 @lilypond[relative=2,ragged-right,verbatim,fragment]
2118 \once \override Glissando #'style = #'dashed-line
2120 \override Glissando #'style = #'dotted-line
2122 \override Glissando #'style = #'zigzag
2124 \override Glissando #'style = #'trill
2128 The information that determines the end-points is computed
2129 on-the-fly for every graphic object, but it is possible to
2132 @lilypond[relative=2,ragged-right,verbatim,fragment]
2134 \once \override Glissando #'bound-details #'right #'Y = #-2
2138 The @code{Glissando} object, like any other using the
2139 @code{ly:line-interface::print} routine, carries a nested
2140 association list. In the above statement, the value for @code{Y}
2141 is set to @code{-2} for the association list corresponding to the
2142 right end point. Of course, it is also possible to adjust the
2143 left side with @code{left} instead of @code{right}.
2145 If @code{Y} is not set, the value is computed from the vertical
2146 position of right attachment point of the spanner.
2148 In case of a line break, the values for the span-points are
2149 extended with contents of the @code{left-broken} and
2150 @code{right-broken} sublists, for example
2152 @lilypond[relative=2,ragged-right,verbatim,fragment]
2153 \override Glissando #'breakable = ##T
2154 \override Glissando #'bound-details #'right-broken #'Y = #-3
2155 c1 \glissando \break
2159 The following properties can be used for the
2163 This sets the Y-coordinate of the end point, in staff space. By
2164 default, it is the center of the bound object, so for a glissando
2165 it points to the vertical center of the note head.
2167 For horizontal spanners, such as text spanner and trill spanners,
2168 it is hardcoded to 0.
2171 This determines where the line starts and ends in X-direction,
2172 relative to the bound object. So, a value of @code{-1} (or
2173 @code{LEFT}) makes the line start/end at the left side of the note
2174 head it is attached to.
2177 This is the absolute coordinate of the end point. It is usually
2178 computed on the fly, and there is little use in overriding it.
2181 Line spanners may have symbols at the beginning or end, which is
2182 contained in this sub-property. This is for internal use, it is
2183 recommended to use @code{text}.
2186 This is a markup that is evaluated to yield stencil. It is used
2187 to put @i{cresc.} and @i{tr} on horizontal spanners.
2189 @lilypond[quote,ragged-right,fragment,relative=2,verbatim]
2190 \override TextSpanner #'bound-details #'left #'text
2191 = \markup { \small \bold Slower }
2192 c2\startTextSpan b c a\stopTextSpan
2195 @item stencil-align-dir-y
2196 @item stencil-offset
2197 Without setting this, the stencil is simply put there at the
2198 end-point, as defined by the @code{X} and @code{Y} sub properties.
2199 Setting either @code{stencil-align-dir-y} or @code{stencil-offset}
2200 will move the symbol at the edge relative to the end point of the
2203 @lilypond[relative=1,fragment,verbatim]
2204 \override TextSpanner #'bound-details
2205 #'left #'stencil-align-dir-y = #DOWN
2206 \override TextSpanner #'bound-details
2207 #'right #'stencil-align-dir-y = #UP
2209 \override TextSpanner #'bound-details
2210 #'left #'text = #"gggg"
2211 \override TextSpanner #'bound-details
2212 #'right #'text = #"hhhh"
2213 c4^\startTextSpan c c c \stopTextSpan
2217 Setting this sub property to @code{#t} produce an arrowhead at the
2221 This sub property controls the space between the specified
2222 end-point of the line and the actual end. Without padding, a
2223 glissando would start and end in the center of each note head.
2227 @c TODO: Move to 5.4.4
2229 The music function \endSpanners terminates spanners and hairpins
2230 after exactly one note.
2232 @lilypond[verbatim,quote,ragged-right,relative=2,fragment]
2234 c2 \startTextSpan c2
2238 When using \endSpanners it is not necessary to close
2239 \startTextSpan with \stopTextSpan, nor is it necessary to close
2246 Internals Reference: @rinternals{TextSpanner},
2247 @rinternals{Glissando}, @rinternals{VoiceFollower},
2248 @rinternals{TrillSpanner},
2249 @rinternals{line-spanner-interface}.
2252 @node Rotating objects
2253 @subsection Rotating objects
2255 Both layout objects and elements of markup text can be rotated by
2256 any angle about any point, but the method of doing so differs.
2259 * Rotating layout objects::
2263 @node Rotating layout objects
2264 @unnumberedsubsubsec Rotating layout objects
2266 @cindex rotating objects
2267 @cindex objects, rotating
2269 All layout objects which support the @code{grob-interface} can be
2270 rotated by setting their @code{rotation} property. This takes a
2271 list of three items: the angle of rotation counter-clockwise,
2272 and the x and y coordinates of the point relative to the object's
2273 reference point about which the rotation is to be performed. The
2274 angle of rotation is specified in degrees and the coordinates in
2277 The angle of rotation and the coordinates of the rotation point must
2278 be determined by trial and error.
2280 @cindex hairpins, angled
2281 @cindex angled hairpins
2283 There are only a few situations where the rotation of layout
2284 objects is useful; the following example shows one situation where
2287 @lilypond[quote,verbatim,relative=1]
2289 \override Hairpin #'rotation = #'(20 -1 0)
2293 @node Rotating markup
2294 @unnumberedsubsubsec Rotating markup
2296 All markup text can be rotated to lie at any angle by prefixing it
2297 with the @code{\rotate} command. The command takes two arguments:
2298 the angle of rotation in degrees counter-clockwise and the text to
2299 be rotated. The extents of the text are not rotated: they take
2300 their values from the extremes of the x and y coordinates of the
2301 rotated text. In the following example the
2302 @code{outside-staff-priority} property for text is set to @code{#f}
2303 to disable the automatic collision avoidance, which would push some
2304 of the text too high.
2306 @lilypond[quote,verbatim,relative=1]
2307 \override TextScript #'outside-staff-priority = ##f
2308 g4^\markup { \rotate #30 "a G" }
2309 b^\markup { \rotate #30 "a B" }
2310 des^\markup { \rotate #30 "a D-Flat" }
2311 fis^\markup { \rotate #30 "an F-Sharp" }
2315 @node Aligning objects
2316 @subsection Aligning objects
2318 @c FIXME Write this section
2321 @node Advanced tweaks
2322 @section Advanced tweaks
2325 * Vertical grouping of grobs::
2326 * Modifying ends of spanners::
2327 * Modifying stencils::
2328 * Modifying shapes::
2334 @node Vertical grouping of grobs
2335 @subsection Vertical grouping of grobs
2337 @c FIXME Expand this section
2339 The VerticalAlignment and VerticalAxisGroup grobs work together.
2340 VerticalAxisGroup groups together different grobs like Staff, Lyrics,
2341 etc. VerticalAlignment then vertically aligns the different grobs
2342 grouped together by VerticalAxisGroup. There is usually only one
2343 VerticalAlignment per score but every Staff, Lyrics, etc. has its own
2347 @node Modifying ends of spanners
2348 @subsection Modifying ends of spanners
2350 @c FIXME Write this section
2352 @node Modifying stencils
2353 @subsection Modifying stencils
2355 @c FIXME Write this section
2357 @node Modifying shapes
2358 @subsection Modifying shapes
2360 @c FIXME Write this section
2361 @c Discussion of Bezier curves and the control-points property
2363 @node Discussion of specific tweaks
2364 @section Discussion of specific tweaks
2367 * old Contexts explained::
2371 @node old Contexts explained
2372 @subsection old Contexts explained
2374 @c FIXME Delete this section? It is in LM
2375 @c Or leave heading and go on from LM?
2377 When music is printed, a lot of notational elements must be added to the
2378 output. For example, compare the input and output of the following example:
2380 @lilypond[quote,verbatim,relative=2,fragment]
2384 The input is rather sparse, but in the output, bar lines, accidentals,
2385 clef, and time signature are added. LilyPond @emph{interprets} the
2386 input. During this step, the musical information is inspected in time
2387 order, similar to reading a score from left to right. While reading
2388 the input, the program remembers where measure boundaries are, and which
2389 pitches require explicit accidentals. This information can be presented on
2390 several levels. For example, the effect of an accidental is limited
2391 to a single staff, while a bar line must be synchronized across the
2394 Within LilyPond, these rules and bits of information are grouped in
2395 @emph{Contexts}. Some examples of contexts are @code{Voice},
2396 @code{Staff}, and @code{Score}. They are hierarchical, for
2397 example: a @code{Staff} can contain many @code{Voice}s, and a
2398 @code{Score} can contain many @code{Staff} contexts.
2401 @sourceimage{context-example,5cm,,}
2404 Each context has the responsibility for enforcing some notation rules,
2405 creating some notation objects and maintaining the associated
2406 properties. For example, the @code{Voice} context may introduce an
2407 accidental and then the @code{Staff} context maintains the rule to
2408 show or suppress the accidental for the remainder of the measure. The
2409 synchronization of bar lines is handled at @code{Score} context.
2411 However, in some music we may not want the bar lines to be
2412 synchronized -- consider a polymetric score in 4/4 and 3/4 time. In
2413 such cases, we must modify the default settings of the @code{Score}
2414 and @code{Staff} contexts.
2416 For very simple scores, contexts are created implicitly, and you need
2417 not be aware of them. For larger pieces, such as anything with more
2418 than one staff, they must be
2419 created explicitly to make sure that you get as many staves as you
2420 need, and that they are in the correct order. For typesetting pieces
2421 with specialized notation, it can be useful to modify existing or
2422 to define new contexts.
2425 A complete description of all available contexts is in the program
2428 @rinternals{Contexts}.
2431 Translation @expansion{} Context.
2434 @c [TODO: describe propagation]