2 @node Changing defaults
3 @chapter Changing defaults
6 The purpose of LilyPond's design is to provide the finest output
7 quality as a default. Nevertheless, it may happen that you need to
8 change that default layout. The layout is controlled through a large
9 number of proverbial ``knobs and switches.'' This chapter does not
10 list each and every knob. Rather, it outlines what groups of controls
11 are available, and it explains how to lookup which knob to use for a
14 The controls are available for tuning are described in a separate
15 document, the @internalsref{Program reference} manual. This manual
16 lists all different variables, functions and options available in
17 LilyPond. It is available as a HTML document, which is available
18 @uref{http://lilypond.org/doc/Documentation/user/out-www/lilypond-internals/,on-line},
19 but is also included with the LilyPond documentation package.
21 There are three areas where the default settings may be changed:
24 @item Output: changing the appearance of individual
25 objects. For example, changing stem directions, or the location of
28 @item Context: changing aspects of the translation from music events to
29 notation. For example, giving each staff a separate time signature.
31 @item Global layout: changing the appearance of the spacing, line
32 breaks and page dimensions.
35 Then, there are separate systems for typesetting text (like
36 @emph{ritardando}) and selecting different fonts. This chapter also
39 Internally, LilyPond uses Scheme (a LISP dialect) to provide
40 infrastructure. Overriding layout decisions in effect accesses the
41 program internals, so it is necessary to learn a (very small) subset
42 of Scheme. That is why this chapter starts with a short tutorial on
43 entering numbers, lists, strings and symbols in Scheme.
48 * Interpretation contexts::
57 @section Scheme tutorial
61 @cindex Scheme, in-line code
62 @cindex accessing Scheme
63 @cindex evaluating Scheme
66 LilyPond uses the Scheme programming language, both as part of the
67 input syntax, and as internal mechanism to glue together modules of
68 the program. This section is a very brief overview of entering data in
69 Scheme.@footnote{If you want to know more about Scheme, see
70 @uref{http://www.schemers.org}.}
72 The most basic thing of a language is data: numbers, character
73 strings, lists, etc. Here is a list of data types that are relevant to
78 Boolean values are True or False. The Scheme for True is @code{#t}
79 and False is @code{#f}.
81 Numbers are entered in the standard fashion,
82 @code{1} is the (integer) number one, while @code{-1.5} is a
83 floating point number (a non-integer number).
85 Strings are enclosed in double quotes,
90 Strings may span several lines
97 Quotation marks and newlines can also be added with so-called escape
98 sequences. The string @code{a said "b"} is entered as
103 Newlines and backslashes are escaped with @code{\n} and @code{\\}
108 In a music file, snippets of Scheme code are introduced with the hash
109 mark @code{#}. So, the previous examples translated in LilyPondese are
120 For the rest of this section, we will assume that the data is entered
121 in a music file, so we add @code{#}s everywhere.
123 Scheme can be used to do calculations. It uses @emph{prefix}
124 syntax. Adding 1 and 2 is written as @code{(+ 1 2)} rather than the
132 The arrow @result{} shows that the result of evaluating @code{(+ 1 2)}
133 is @code{3}. Calculations may be nested: the result of a function may
134 be used for another calculation.
142 These calculations are examples of evaluations: an expression like
143 @code{(* 3 4)} is replaced by its value @code{12}. A similar thing
144 happens with variables. After defining a variable
150 variables can also be used in expressions, here
153 twentyFour = #(* 2 twelve)
156 the number 24 is stored in the variable @code{twentyFour}.
158 The @emph{name} of a variable is also an expression, similar to a
159 number or a string. It is entered as
165 The quote mark @code{'} prevents Scheme interpreter from substituting
166 @code{24} for the @code{twentyFour}. Instead, we get the name
169 This syntax will be used very frequently, since many of the layout
170 tweaks involve assigning (Scheme) values to internal variables, for
174 \override Stem #'thickness = #2.6
177 This instruction adjusts the appearance of stems. The value @code{2.6}
178 is put into a the @code{thickness} variable of a @code{Stem}
179 object. This makes stems almost twice as thick as their normal size.
180 To distinguish between variables defined in input files (like
181 @code{twentyFour} in the example above), and internal variables, we
182 will call the latter ``properties.'' So, the stem object has a
183 @code{thickness} property.
185 Two-dimensional offsets (X and Y coordinates) as well as object sizes
186 (intervals with a left and right point) are entered as @code{pairs}. A
187 pair@footnote{In Scheme terminology, the pair is called @code{cons},
188 and its two elements are called car and cdr respectively.} is entered
189 as @code{(first . second)}, and like symbols, they must be quoted,
192 \override TextScript #'extra-offset = #'(1 . 2)
195 This assigns the pair (1, 2) to @code{extra-offset} variable of the
196 TextScript object. This moves the object 1 staff space to the right,
199 The two elements of a pair may be arbitrary values, for example
204 #'("blah-blah" . 3.14159265)
207 A list is entered by enclosing its elements in parentheses, and adding
208 a quote. For example,
214 We have been using lists all along. A calculation, like @code{(+ 1
215 2)} is also a list (containing the symbol @code{+} and the numbers 1
216 and 2). Normally lists are interpreted as calculations, and the Scheme
217 interpreter substitutes the outcome of the calculation. To enter a
218 list, we stop evaluation. This is done by quoting the list with a
219 quote @code{'} symbol. For calculations, do not use a quote.
221 Inside a quoted list or pair, there is no need to quote anymore. The
222 following is a pair of symbols, a list of symbols and a list of lists
227 #'(staff clef key-signature)
232 @node Interpretation contexts
233 @section Interpretation contexts
235 When music is printed, a lot of things notation elements must be added
236 to the input, which is often bare bones. For example, compare the
237 input and output of the following example
239 @lilypond[verbatim,relative=2]
243 The input is rather sparse, but in the output, bar lines, accidentals,
244 clef and time signature are added. LilyPond @emph{interprets} the
245 input. During this step, the musical information is inspected in time
246 order, similar to reading a score from left to right. While reading,
247 the program remembers where measure boundaries are, and what pitches
248 need explicit accidentals.
250 This is contextual information. and it can be present on several
251 levels. For example, the effect of an accidental is limited to a
252 single stave, while a bar line must be synchronized across the entire
253 score. To match this hierarchy, LilyPond's interpretation step is
254 hierarchical. There are interpretation contexts, like
255 @context{Voice}, Staff and Score, and each level can maintain its own
258 Full description of all available contexts is in the program
261 @internalsref{Contexts}
264 Translation @arrow{} Context.
267 @c [TODO: describe propagation]
271 * Creating contexts::
272 * Changing context properties on the fly ::
273 * Modifying context plug-ins::
274 * Layout tunings within contexts::
275 * Changing context default settings::
276 * Defining new contexts::
277 * Which properties to change::
280 @node Creating contexts
281 @subsection Creating contexts
283 For scores with only one voice and one staff, correct contexts are
284 created automatically. For more complex scores, it is necessary to
285 instantiate them by hand. There are three commands to do this.
287 The easiest command is @code{\new}, and it also the quickest to type.
288 It is prepended to a music expression, for example
291 \new @var{type} @var{music expression}
295 where @var{type} is a context name (like @code{Staff} or
296 @code{Voice}). This command creates a new context, and starts
297 interpreting @var{music expression} with that.
299 A practical application of @code{\new} is a score with many
300 staves. Each part that should be on its own staff, gets a @code{\new
303 @lilypond[verbatim,relative=2,raggedright]
304 << \new Staff { c4 c }
309 Like @code{\new}, the @code{\context} command also directs a music
310 expression to a context object, but gives the context an extra name. The
314 \context @var{type} = @var{id} @var{music}
317 This form will search for an existing context of type @var{type}
318 called @var{id}. If that context does not exist yet, it is created.
319 This is useful if the context referred to later on. For example, when
320 setting lyrics the melody is in a named context
323 \context Voice = "@b{tenor}" @var{music}
327 so the texts can be properly aligned to its notes,
330 \new Lyrics \lyricsto "@b{tenor}" @var{lyrics}
335 Another possibility is funneling two different music expressions into
336 one context. In the following example, articulations and notes are
340 music = \notes { c4 c4 }
341 arts = \notes { s4-. s4-> }
344 They are combined by sending both to the same @context{Voice} context,
347 << \new Staff \context Voice = "A" \music
348 \context Voice = "A" \arts
351 @lilypond[raggedright]
352 music = \notes { c4 c4 }
353 arts = \notes { s4-. s4-> }
355 \notes \relative c'' << \new Staff \context Voice = "A" \music
356 \context Voice = "A" \arts
363 The third command for creating contexts is
365 \context @var{type} @var{music}
370 This is similar to @code{\context} with @code{= @var{id}}, but matches
371 any context of type @var{type}, regardless of its given name.
373 This variant is used with music expressions that can be interpreted at
374 several levels. For example, the @code{\applyoutput} command (see
375 @ref{Running a function on all layout objects}). Without an explicit
376 @code{\context}, it is usually is applied to @context{Voice}
379 \applyoutput #@var{function} % apply to Voice
382 To have it interpreted at @context{Score} or @context{Staff} level use
386 \context Score \applyoutput #@var{function}
387 \context Staff \applyoutput #@var{function}
391 @node Changing context properties on the fly
392 @subsection Changing context properties on the fly
394 Each context can have different @emph{properties}, variables contained
395 in that context. They can be changed during the interpretation step.
396 This is achieved by inserting the @code{\set} command in the music,
399 @code{\set } @var{context}@code{.}@var{prop}@code{ = #}@var{value}
403 @lilypond[verbatim,relative=2]
405 \set Score.skipBars = ##t
409 This command skips measures that have no notes. The result is that
410 multi rests are condensed. The value assigned is a Scheme object. In
411 this case, it is @code{#t}, the boolean True value.
413 If the @var{context} argument is left out, then the current bottom-most
414 context (typically @context{ChordNames}, @context{Voice} or
415 @context{Lyrics}) is used. In this example,
417 @lilypond[verbatim,relative=2]
419 \set autoBeaming = ##f
424 the @var{context} argument to @code{\set} is left out, and the current
425 @internalsref{Voice} is used.
427 Contexts are hierarchical, so if a bigger context was specified, for
428 example @context{Staff}, then the change would also apply to all
429 @context{Voice}s in the current stave. The change is applied
430 `on-the-fly', during the music, so that the setting only affects the
431 second group of eighth notes.
433 There is also an @code{\unset} command,
435 @code{\set }@var{context}@code{.}@var{prop}
439 which removes the definition of @var{prop}. This command only removes
440 the definition if it is set in @var{context}. In
443 \set Staff.autoBeaming = ##f
444 \unset Voice.autoBeaming
448 the current @context{Voice} does not have the property, and the
449 definition at @context{Staff} level remains intact. Like @code{\set},
450 the @var{context} argument does not have to be specified for a bottom
453 Settings that should only apply to a single time-step can be entered
454 easily with @code{\once}, for example in
456 @lilypond[verbatim,relative=2]
458 \once \set fontSize = #4.7
463 the property @code{fontSize} is unset automatically after the second
466 A full description of all available context properties is in the
467 program reference, see
469 @internalsref{Tunable-context-properties}.
472 Translation @arrow{} Tunable context properties.
476 @node Modifying context plug-ins
477 @subsection Modifying context plug-ins
479 Notation contexts (like Score and Staff) not only store properties,
480 they also contain plug-ins, called ``engravers'' that create notation
481 elements. For example, the Voice context contains a
482 @code{Note_head_engraver} and the Staff context contains a
483 @code{Key_signature_engraver}.
485 For a full a description of each plug-in, see
487 @internalsref{Engravers}
490 Program reference @arrow Translation @arrow{} Engravers.
492 Every context described in
494 @internalsref{Contexts}
497 Program reference @arrow Translation @arrow{} Context.
499 lists the engravers used for that context.
502 It can be useful to shuffle around these plug-ins. This is done by
503 starting a new context, with @code{\new} or @code{\context}, and
504 modifying it like this,
507 \new @var{context} \with @{
517 where the @dots{} should be the name of an engraver. Here is a simple
518 example which removes @code{Time_signature_engraver} and
519 @code{Clef_engraver} from a @code{Staff} context,
521 @lilypond[relative=1, verbatim]
526 \remove "Time_signature_engraver"
527 \remove "Clef_engraver"
534 In the second stave there are no time signature or clef symbols. This
535 is a rather crude method of making objects disappear, it will affect
536 the entire staff. The spacing will be adversely influenced too. A more
537 sophisticated methods of blanking objects is shown in @ref{Common
540 The next example shows a practical application. Bar lines and time
541 signatures are normally synchronized across the score. This is done
542 by the @code{Timing_engraver}. This plug-in keeps an administration of
543 time signature, location within the measure, etc. By moving the
544 @code{Timing_engraver} engraver from Score to Staff context, we can
545 have score where each staff has its own time signature.
547 @cindex polymetric scores
550 @lilypond[relative=1,raggedright,verbatim]
552 \remove "Timing_engraver"
555 \consists "Timing_engraver"
561 \consists "Timing_engraver"
570 @node Layout tunings within contexts
571 @subsection Layout tunings within contexts
573 Each context is responsible for creating certain types of graphical
574 objects. The settings used for printing these objects are also stored by
575 context. By changing these settings, the appearance of objects can be
578 The syntax for this is
581 \override @var{context}.@var{name}@code{ #'}@var{property} = #@var{value}
584 Here @var{name} is the name of a graphical object, like @code{Stem} or
585 @code{NoteHead}. @var{property} is an internal variable of the
586 formatting system (`grob property' or `layout property'). It is a
587 symbol, so it must be quoted. The subsection @ref{Constructing a
588 tweak} explains what to fill in for @var{name}, @var{property} and
589 @var{value}. Here we only discuss functionality of this command.
594 \override Staff.Stem #'thickness = #4.0
598 makes stems thicker (the default is 1.3, with staff line thickness as a
599 unit). Since the command specifies @context{Staff} as context, it only
600 applies to the current staff. Other staves will keep their normal
601 appearance. Here we see the command in action:
603 @lilypond[verbatim,relative=2]
605 \override Staff.Stem #'thickness = #4.0
611 The @code{\override} command is executed during the interpreting phase,
612 and changes the definition of the @code{Stem} within
613 @context{Staff}. After the command all stems are thickened.
615 Analogous to @code{\set}, the @var{context} argument may be left out,
616 causing it to default to @context{Voice} and adding @code{\once} applies
617 the change during only one timestep
619 @lilypond[verbatim,relative=2]
621 \once \override Stem #'thickness = #4.0
626 The @code{\override} must be done before the object is
627 started. Therefore, when altering @emph{Spanner} objects, like slurs or
628 beams, the @code{\override} command must be executed at the moment that
629 the object is created. In this example,
632 @lilypond[verbatim,relative=2]
633 \override Slur #'thickness = #3.0
635 \override Beam #'thickness = #0.6
640 the slur is fatter and the beam is not. This is because the command for
641 @code{Beam} comes after the Beam is started. Therefore it has no effect.
643 Analogous to @code{\unset}, the @code{\revert} command for a context
644 undoes a @code{\override} command; like with @code{\unset}, it only
645 affects settings that were made in the same context. In other words, the
646 @code{\revert} in the next example does not do anything.
649 \override Voice.Stem #'thickness = #4.0
650 \revert Staff.Stem #'thickness
658 Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
659 @internalsref{PropertySet}, @internalsref{All-backend-properties}, and
660 @internalsref{All-layout-objects}.
665 The back-end is not very strict in type-checking object properties.
666 Cyclic references in Scheme values for properties can cause hangs
670 @node Changing context default settings
671 @subsection Changing context default settings
673 The adjustments of the previous chapters can also be entered separate
674 from the music, in the @code{\paper} block,
683 \override Stem #'thickness
684 \remove "Time_signature_engraver"
695 takes the existing definition @context{Staff} from the identifier
696 @code{StaffContext}. This works analogously other contexts, so the
697 existing definition of @code{Voice} is in
698 @code{\VoiceContext}.
703 \override Stem #'thickness
704 \remove "Time_signature_engraver"
708 affect all staves in the score.
710 The @code{\set} keyword is optional within the @code{\paper} block, so
723 It is not possible to collect changes in a variable, and apply them to
724 one @code{\context} definition by referencing that variable.
727 @node Defining new contexts
728 @subsection Defining new contexts
730 Specific contexts, like @context{Staff} and @code{Voice} are made of
731 simple building blocks, and it is possible to compose engraver
732 plug-ins in different combinations, thereby creating new types of
735 The next example shows how to build a different type of
736 @context{Voice} context from scratch. It will be similar to
737 @code{Voice}, but print centered slash noteheads only. It can be used
738 to indicate improvisation in Jazz pieces,
740 @lilypond[raggedright]
743 \type "Engraver_group_engraver"
744 \consists "Note_heads_engraver"
745 \consists "Text_engraver"
746 \consists Pitch_squash_engraver
747 squashedPosition = #0
748 \override NoteHead #'style = #'slash
749 \override Stem #'transparent = ##t
752 \context { \StaffContext
753 \accepts "ImproVoice"
755 \score { \notes \relative c'' {
756 a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
757 c4 c^"undress" c_"while playing :)" c }
763 These settings are again done within a @code{\context} block inside a
774 In the following discussion, the example input shown should go on the
775 @dots{} of the previous fragment.
777 First, name the context gets a name. Instead of @context{Voice} it
778 will be called @context{ImproVoice},
784 Since it is similar to the @context{Voice}, we want commands that work
785 on (existing) @context{Voice}s to remain working. This is achieved by
786 giving the new context an alias @context{Voice},
792 The context will print notes, and instructive texts
795 \consists Note_heads_engraver
796 \consists Text_engraver
799 but only on the center line,
802 \consists Pitch_squash_engraver
803 squashedPosition = #0
806 The @internalsref{Pitch_squash_engraver} modifies note heads (created
807 by @internalsref{Note_heads_engraver}) and sets their vertical
808 position to the value of @code{squashedPosition}, in this case
809 @code{0}, the center line.
811 The notes look like a slash, without a stem,
814 \override NoteHead #'style = #'slash
815 \override Stem #'transparent = ##t
819 All these plug-ins have to cooperate, and this is achieved with a
820 special plug-in, which must be marked with the keyword @code{\type}.
821 This should always be @internalsref{Engraver_group_engraver},
824 \type "Engraver_group_engraver"
832 \type "Engraver_group_engraver"
833 \consists "Note_heads_engraver"
834 \consists "Text_script_engraver"
835 \consists Pitch_squash_engraver
836 squashedPosition = #0
837 \override NoteHead #'style = #'slash
838 \override Stem #'transparent = ##t
843 Contexts form hierarchies. We want to hang the @context{ImproVoice}
844 under @context{Staff}, just like normal @code{Voice}s. Therefore, we
845 modify the @code{Staff} definition with the @code{\accepts}
846 command,@footnote{The opposite of @code{\accepts} is @code{\denies},
847 which is sometimes when reusing existing context definitions. }
858 Putting both into a @code{\paper} block, like
868 \accepts "ImproVoice"
873 Then the output at the start of this subsection can be entered as
877 \notes \relative c'' {
882 c c_"while playing :)"
891 @node Which properties to change
892 @subsection Which properties to change
895 There are many different properties. Not all of them are listed in
896 this manual. However, the program reference lists them all in the
897 section @internalsref{Context-properties}, and most properties are
898 demonstrated in one of the
900 @uref{../../../input/test/out-www/collated-files.html,tips-and-tricks}
909 @section Tuning output
911 In the previous section, we have already touched on a command that
912 changes layout details, the @code{\override} command. In this section,
913 we will look at in more detail how to use the command in practice.
914 First, we will give a a few versatile commands, which are sufficient
915 for many situations. The next section will discuss general use of
920 -nmost adjustments simply
927 There are situations where default layout decisions are not
928 sufficient. In this section we discuss ways to override these
931 Formatting is internally done by manipulating so called objects
932 (graphic objects). Each object carries with it a set of properties
933 (object or layout properties) specific to that object. For example, a
934 stem object has properties that specify its direction, length and
937 The most direct way of tuning the output is by altering the values of
938 these properties. There are two ways of doing that: first, you can
939 temporarily change the definition of one type of object, thus
940 affecting a whole set of objects. Second, you can select one specific
941 object, and set a layout property in that object.
943 Do not confuse layout properties with translation
944 properties. Translation properties always use a mixed caps style
945 naming, and are manipulated using @code{\set} and @code{\unset}:
947 \set Context.propertyName = @var{value}
950 Layout properties are use Scheme style variable naming, i.e. lower
951 case words separated with dashes. They are symbols, and should always
952 be quoted using @code{#'}. For example, this could be an imaginary
953 layout property name:
955 #'layout-property-name
961 * Constructing a tweak::
962 * Navigating the program reference::
963 * Layout interfaces::
964 * Determining the grob property::
970 @subsection Common tweaks
972 Some overrides are so common that predefined commands are provided as
973 a short cut. For example, @code{\slurUp} and @code{\stemDown}. These
974 commands are described in
978 @ref{Notation manual}, under the sections for slurs and stems
981 The exact tuning possibilities for each type of layout object are
982 documented in the program reference of the respective
983 object. However, many layout objects share properties, which can be
984 used to apply generic tweaks. We mention a couple of these:
987 @item The @code{extra-offset} property, which
988 @cindex @code{extra-offset}
989 has a pair of numbers as value, moves around objects in the printout.
990 The first number controls left-right movement; a positive number will
991 move the object to the right. The second number controls up-down
992 movement; a positive number will move it higher. The units of these
993 offsets are staff-spaces. The @code{extra-offset} property is a
994 low-level feature: the formatting engine is completely oblivious to
997 In the following example, the second fingering is moved a little to
998 the left, and 1.8 staff space downwards:
1000 @cindex setting object properties
1002 @lilypond[relative=1,verbatim]
1005 \once \override Fingering
1006 #'extra-offset = #'(-0.3 . -1.8)
1011 Setting the @code{transparent} property will cause an object to be printed
1012 in `invisible ink': the object is not printed, but all its other
1013 behavior is retained. The object still takes up space, it takes part in
1014 collisions, and slurs, and ties and beams can be attached to it.
1016 @cindex transparent objects
1017 @cindex removing objects
1018 @cindex hiding objects
1019 @cindex invisible objects
1020 The following example demonstrates how to connect different voices
1021 using ties. Normally, ties only connect two notes in the same
1022 voice. By introducing a tie in a different voice, and blanking a stem
1023 in that voice, the tie appears to cross voices:
1025 @lilypond[fragment,relative=2,verbatim]
1027 \once \override Stem #'transparent = ##t
1035 The @code{padding} property for objects with
1036 @cindex @code{padding}
1037 @code{side-position-interface} can be set to increase distance between
1038 symbols that are printed above or below notes. We only give an
1039 example; a more elaborate explanation is in @ref{Constructing a
1042 @lilypond[relative=1,verbatim]
1044 \override Script #'padding = #3
1050 More specific overrides are also possible. The following section
1051 discusses in depth how to figure out these statements for yourself.
1054 @node Constructing a tweak
1055 @subsection Constructing a tweak
1057 The general procedure of changing output, that is, entering
1061 \override Voice.Stem #'thickness = #3.0
1065 means that we have to determine these bits of information:
1068 @item The context, here: @context{Voice}.
1069 @item The layout object, here @code{Stem}.
1070 @item The layout property, here @code{thickness}
1071 @item A sensible value, here @code{3.0}
1075 @cindex internal documentation
1076 @cindex finding graphical objects
1077 @cindex graphical object descriptions
1079 @cindex @code{\override}
1081 @cindex internal documentation
1083 We demonstrate how to glean this information from the notation manual
1084 and the program reference.
1086 The program reference is a set of HTML pages, which is part of the
1087 documentation package. On Unix systems, it is is typically in
1088 @file{/usr/share/doc/lilypond}, if you have them, it is best to
1089 bookmark them in your webbrowser, because you will need them. They
1090 are also available on the web: go to the
1091 @uref{http://lilypond.org,LilyPond website}, click ``Documentation'',
1092 select the correct version, and then click ``Program reference.''
1094 If you have them, use the local HTML files. They will load faster,
1095 and they are exactly matched to LilyPond version installed.
1098 @node Navigating the program reference
1099 @subsection Navigating the program reference
1101 Suppose we want to move the fingering indication in the fragment
1104 @lilypond[relative=2,verbatim]
1110 If you visit the documentation of @code{Fingering} (in @ref{Fingering
1111 instructions}), you will notice that there is written:
1116 Program reference: @internalsref{FingerEvent} and @internalsref{Fingering}.
1120 This fragments points to two parts of the program reference: a page
1121 on @code{FingerEvent} and @code{Fingering}.
1123 The page on @code{FingerEvent} describes the properties of the music
1124 expression for the input @code{-2}. The page contains many links
1125 forward. For example, it says
1128 Accepted by: @internalsref{Fingering_engraver},
1132 That link brings us to the documentation for the Engraver, the
1136 This engraver creates the following layout objects: @internalsref{Fingering}.
1139 In other words, once the @code{FingerEvent}s are interpreted, the
1140 @code{Fingering_engraver} plug-in will process them.
1141 The @code{Fingering_engraver} is also listed to create
1142 @internalsref{Fingering} objects,
1145 Lo and behold, that is also the
1146 second bit of information listed under @b{See also} in the Notation
1147 manual. By clicking around in the program reference, we can follow the
1148 flow of information within the program, either forward (like we did
1149 here), or backwards, following links like this:
1153 @item @internalsref{Fingering}:
1154 @internalsref{Fingering} objects are created by:
1155 @b{@internalsref{Fingering_engraver}}
1157 @item @internalsref{Fingering_engraver}:
1158 Music types accepted: @b{@internalsref{fingering-event}}
1159 @item @internalsref{fingering-event}:
1160 Music event type @code{fingering-event} is in Music objects of type
1161 @b{@internalsref{FingerEvent}}
1164 This path goes against the flow of information in the program: it
1165 starts from the output, and ends at the input event.
1167 The program reference can also be browsed like a normal document. It
1168 contains a chapter on @internalsref{Music definitions}, on
1169 @internalsref{Translation}, and the @internalsref{Backend}. Every
1170 chapter lists all the definitions used, and all properties that may
1174 @node Layout interfaces
1175 @subsection Layout interfaces
1177 @internalsref{Fingering} is a layout object. Such an object is a
1178 symbol within the score. It has properties, which store numbers (like
1179 thicknesses and directions), but also pointers to related objects.
1180 A layout object is also called @emph{grob},
1182 which is short for Graphical Object.
1185 The page for @code{Fingering} lists the definitions for the
1186 @code{Fingering} object. For example, the page says
1189 @code{padding} (dimension, in staff space):
1194 which means that the number will be kept at a distance of at least 0.6
1198 Each layout object may have several functions as a notational or
1199 typographical element. For example, the Fingering object
1200 has the following aspects
1203 @item Its size is independent of the horizontal spacing, unlike slurs or beams
1205 @item It is a piece of text. Granted, it's usually a very short text.
1207 @item That piece of text is set in a font, unlike slurs or beams.
1208 @item Horizontally, the center of the symbol should be aligned to the
1209 center of the notehead
1210 @item Vertically, the symbol is placed next to the note and the staff.
1213 vertical position is also coordinated with other super and subscript
1217 Each of these aspects is captured in a so-called @emph{interface},
1218 which are listed on the @internalsref{Fingering} page at the bottom
1221 This object supports the following interfaces:
1222 @internalsref{item-interface},
1223 @internalsref{self-alignment-interface},
1224 @internalsref{side-position-interface}, @internalsref{text-interface},
1225 @internalsref{text-script-interface}, @internalsref{font-interface},
1226 @internalsref{finger-interface} and @internalsref{grob-interface}
1229 Clicking any of the links will take you to the page of the respective
1230 object interface. Each interface has a number of properties. Some of
1231 them are not user-serviceable (``Internal properties''), but others
1234 We have been talking of `the' @code{Fingering} object, but actually it
1235 does not amount to much. The initialization file
1236 @file{scm/define-grobs.scm} shows the soul of the `object',
1241 (print-function . ,Text_item::print)
1243 (staff-padding . 0.6)
1244 (self-alignment-X . 0)
1245 (self-alignment-Y . 0)
1246 (script-priority . 100)
1247 (font-encoding . number)
1249 (meta . ((interfaces . (finger-interface font-interface
1250 text-script-interface text-interface
1251 side-position-interface self-alignment-interface
1256 as you can see, @code{Fingering} is nothing more than a bunch of
1257 variable settings, and the webpage is directly generated from this
1260 @node Determining the grob property
1261 @subsection Determining the grob property
1264 Recall that we wanted to change the position of the @b{2} in
1266 @lilypond[relative=2,verbatim]
1272 Since the @b{2} is vertically positioned next to its note, we have to
1273 meddle with the interface associated with this positioning. This is
1274 done by @code{side-position-interface}. The page for this interface says
1277 @code{side-position-interface}
1279 Position a victim object (this one) next to other objects (the
1280 support). The property @code{direction} signifies where to put the
1281 victim object relative to the support (left or right, up or down?)
1286 below this description, the variable @code{padding} is described as
1290 (dimension, in staff space)
1292 add this much extra space between objects that are next to each
1297 By increasing the value of @code{padding}, we can move away the
1298 fingering. The following command inserts 3 staff spaces of white
1299 between the note and the fingering:
1301 \once \override Fingering #'padding = #3
1304 Inserting this command before the Fingering object is created,
1305 i.e. before @code{c2}, yields the following result:
1307 @lilypond[relative=2,fragment,verbatim]
1308 \once \override Fingering
1316 In this case, the context for this tweak is @context{Voice}, which
1317 does not have to be specified for @code{\override}. This fact can
1318 also be deduced from the program reference, for the page for the
1319 @internalsref{Fingering_engraver} plug-in says
1322 Fingering_engraver is part of contexts: @dots{} @b{@internalsref{Voice}}
1330 * Selecting font sizes::
1336 @node Selecting font sizes
1337 @subsection Selecting font sizes
1339 The most common thing to change about the appearance of fonts is their
1340 size. The font size of any context can be easily changed by setting
1341 the @code{fontSize} property for that context. Its value is a number:
1342 negative numbers make the font smaller, positive numbers larger. An
1343 example is given below:
1345 @lilypond[fragment,relative=1,verbatim]
1346 c4 c4 \set fontSize = #-3
1349 This command will set @code{font-size} (see below) in all layout
1350 objects in the current context. It does not change the size of
1351 variable symbols, such as beams or slurs.
1353 The font size is set by modifying the @code{font-size} property. Its
1354 value is a number indicating the size relative to the standard size.
1355 Each step up is an increase of approximately 12% of the font size. Six
1356 steps is exactly a factor two. The Scheme function @code{magstep}
1357 converts a @code{font-size} number to a scaling factor.
1359 LilyPond has fonts in different design sizes: the music fonts for
1360 smaller sizes are chubbier, while the text fonts are relatively wider.
1361 Font size changes are achieved by scaling the design size that is
1362 closest to the desired size.
1364 The @code{font-size} mechanism does not work for fonts selected
1365 through @code{font-name}. These may be scaled with
1366 @code{font-magnification}.
1369 One of the uses of @code{fontSize} is to get smaller symbols for cue
1370 notes. An elaborate example of those is in
1371 @inputfileref{input/test,cue-notes.ly}.
1373 @cindex @code{font-style}
1377 The following commands set @code{fontSize} for the current voice.
1379 @cindex @code{\tiny}
1381 @cindex @code{\small}
1383 @cindex @code{\normalsize}
1388 @cindex magnification
1392 @node Font selection
1393 @subsection Font selection
1395 Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
1396 can also be adjusted with a more fine-grained mechanism. By setting
1397 the object properties described below, you can select a different font;
1398 all three mechanisms work for every object that supports
1399 @code{font-interface}:
1403 @item @code{font-encoding}
1404 is a symbol that sets layout of the glyphs. Choices include
1405 @code{text} for normal text, @code{braces} (for piano staff braces),
1406 @code{music} (the standard music font, including ancient glyphs),
1407 @code{dynamic} (for dynamic signs) and @code{number} for the number
1411 @item @code{font-family}
1412 is a symbol indicating the general class of the typeface. Supported are
1413 @code{roman} (Computer Modern), @code{sans} and @code{typewriter}
1415 @item @code{font-shape}
1416 is a symbol indicating the shape of the font, there are typically
1417 several font shapes available for each font family. Choices are
1418 @code{italic}, @code{caps} and @code{upright}.
1420 @item @code{font-series}
1421 is a symbol indicating the series of the font. There are typically several
1422 font series for each font family and shape. Choices are @code{medium}
1427 Fonts selected in the way sketched above come from a predefined style
1430 The font used for printing a object can be selected by setting
1431 @code{font-name}, e.g.
1433 \override Staff.TimeSignature
1434 #'font-name = #"cmr17"
1438 Any font can be used, as long as it is available to @TeX{}. Possible
1439 fonts include foreign fonts or fonts that do not belong to the
1440 Computer Modern font family. The size of fonts selected in this way
1441 can be changed with the @code{font-magnification} property. For
1442 example, @code{2.0} blows up all letters by a factor 2 in both
1446 @cindex font magnification
1452 Init files: @file{ly/declarations-init.ly} contains hints how new
1453 fonts may be added to LilyPond.
1457 No style sheet is provided for other fonts besides the @TeX{}
1458 Computer Modern family.
1460 @cindex font selection
1461 @cindex font magnification
1462 @cindex @code{font-interface}
1466 @section Text markup
1471 @cindex typeset text
1473 LilyPond has an internal mechanism to typeset texts. You can access it
1474 with the keyword @code{\markup}. Within markup mode, you can enter texts
1475 similar to lyrics: simply enter them, surrounded by spaces:
1478 @lilypond[verbatim,fragment,relative=1]
1479 c1^\markup { hello }
1480 c1_\markup { hi there }
1481 c1^\markup { hi \bold there, is \italic anyone home? }
1484 @cindex font switching
1486 The markup in the example demonstrates font switching commands. The
1487 command @code{\bold} and @code{\italic} only apply to the first
1488 following word; enclose a set of texts with braces to apply a command
1491 \markup @{ \bold @{ hi there @} @}
1495 For clarity, you can also do this for single arguments, e.g.
1498 \markup { is \italic { anyone } home }
1501 @cindex font size, texts
1504 In markup mode you can compose expressions, similar to mathematical
1505 expressions, XML documents and music expressions. The braces group
1506 notes into horizontal lines. Other types of lists also exist: you can
1507 stack expressions grouped with @code{<}, and @code{>} vertically with
1508 the command @code{\column}. Similarly, @code{\center-align} aligns
1509 texts by their center lines:
1511 @lilypond[verbatim,fragment,relative=1]
1512 c1^\markup { \column < a bbbb c > }
1513 c1^\markup { \center-align < a bbbb c > }
1514 c1^\markup { \line < a b c > }
1518 Markups can be stored in variables, and these variables
1519 may be attached to notes, like
1521 allegro = \markup { \bold \large { Allegro } }
1522 \notes { a^\allegro b c d }
1526 Some objects have alignment procedures of their own, which cancel out
1527 any effects of alignments applied to their markup arguments as a
1528 whole. For example, the @internalsref{RehearsalMark} is horizontally
1529 centered, so using @code{\mark \markup @{ \left-align .. @}} has no
1532 Similarly, for moving whole texts over notes with
1533 @code{\raise}, use the following trick:
1535 "" \raise #0.5 raised
1538 The text @code{raised} is now raised relative to the empty string
1539 @code{""} which is not visible. Alternatively, complete objects can
1540 be moved with layout properties such as @code{padding} and
1541 @code{extra-offset}.
1547 Init files: @file{scm/new-markup.scm}.
1552 Text layout is ultimately done by @TeX{}, which does kerning of
1553 letters. LilyPond does not account for kerning, so texts will be
1554 spaced slightly too wide.
1556 Syntax errors for markup mode are confusing.
1558 Markup texts cannot be used in the titling of the @code{\header}
1559 field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
1565 * Overview of text markup commands::
1568 @node Overview of text markup commands
1569 @subsection Overview of text markup commands
1571 @include markup-commands.tely
1575 @section Global layout
1577 The global layout determined by three factors: the page layout, the
1578 line breaks and the spacing. These all influence each other. The
1579 choice of spacing determines how densely each system of music is set,
1580 which influences where line breaks breaks are chosen, and thus
1581 ultimately how many pages a piece of music takes. This section
1582 explains how to tune the algorithm for spacing.
1584 Globally spoken, this procedure happens in three steps: first,
1585 flexible distances (``springs'') are chosen, based on durations. All
1586 possible line breaking combination are tried, and the one with the
1587 best results---a layout that has uniform density and requires as
1588 little stretching or cramping as possible---is chosen. When the score
1589 is processed by @TeX{}, each page is filled with systems, and page breaks
1590 are chosen whenever the page gets full.
1595 * Setting global staff size::
1596 * Vertical spacing::
1597 * Horizontal spacing::
1603 @node Setting global staff size
1604 @subsection Setting global staff size
1606 @cindex font size, setting
1607 @cindex staff size, setting
1608 @cindex @code{paper} file
1610 The Feta font provides musical symbols at eight different
1611 sizes. Each font is tuned for a different staff size: at smaller sizes
1612 the font gets heavier, to match the relatively heavier staff lines.
1613 The recommended font sizes are listed in the following table:
1615 @multitable @columnfractions .25 .25 .25 .25
1618 @tab @b{staff height (pt)}
1619 @tab @b{staff height (mm)}
1661 @c modern rental material ?
1665 These fonts are available in any sizes. The context property
1666 @code{fontSize} and the layout property @code{staff-space} (in
1667 @internalsref{StaffSymbol}) can be used to tune size for individual
1668 staves. The size of individual staves are relative to the global size,
1669 which can be set in the following manner:
1672 #(set-global-staff-size 14)
1675 This sets the global default size to 14pt staff height, and scales all
1680 This manual: @ref{Selecting font sizes}.
1685 * Vertical spacing::
1686 * Horizontal spacing::
1691 @node Vertical spacing
1692 @subsection Vertical spacing
1694 @cindex vertical spacing
1695 @cindex distance between staves
1696 @cindex staff distance
1697 @cindex between staves, distance
1698 @cindex staves per page
1699 @cindex space between staves
1701 The height of each system is determined automatically by LilyPond, to
1702 keep systems from bumping into each other, some minimum distances are
1703 set. By changing these, you can put staves closer together, and thus
1704 put more systems onto one page.
1706 Normally staves are stacked vertically. To make
1707 staves maintain a distance, their vertical size is padded. This is
1708 done with the property @code{minimumVerticalExtent}. It takes a pair
1709 of numbers, so if you want to make it smaller from its, then you could
1712 \set Staff.minimumVerticalExtent = #'(-4 . 4)
1714 This sets the vertical size of the current staff to 4 staff spaces on
1715 either side of the center staff line. The argument of
1716 @code{minimumVerticalExtent} is interpreted as an interval, where the
1717 center line is the 0, so the first number is generally negative. The
1718 staff can be made larger at the bottom by setting it to @code{(-6
1721 The piano staves are handled a little differently: to make cross-staff
1722 beaming work correctly, it is necessary that the distance between staves
1723 is fixed beforehand. This is also done with a
1724 @internalsref{VerticalAlignment} object, created in
1725 @internalsref{PianoStaff}. In this object the distance between the
1726 staves is fixed by setting @code{forced-distance}. If you want to
1727 override this, use a @code{\context} block as follows:
1732 \override VerticalAlignment #'forced-distance = #9
1737 This would bring the staves together at a distance of 9 staff spaces,
1738 measured from the center line of each staff.
1742 Internals: Vertical alignment of staves is handled by the
1743 @internalsref{VerticalAlignment} object.
1748 @node Horizontal spacing
1749 @subsection Horizontal Spacing
1751 The spacing engine translates differences in durations into
1752 stretchable distances (``springs'') of differing lengths. Longer
1753 durations get more space, shorter durations get less. The shortest
1754 durations get a fixed amount of space (which is controlled by
1755 @code{shortest-duration-space} in the @internalsref{SpacingSpanner} object).
1756 The longer the duration, the more space it gets: doubling a
1757 duration adds a fixed amount (this amount is controlled by
1758 @code{spacing-increment}) of space to the note.
1760 For example, the following piece contains lots of half, quarter and
1761 8th notes, the eighth note is followed by 1 note head width (NHW).
1762 The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
1763 @lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8
1767 Normally, @code{shortest-duration-space} is set to 1.2, which is the
1768 width of a note head, and @code{shortest-duration-space} is set to
1769 2.0, meaning that the shortest note gets 2 NHW (i.e. 2 times
1770 @code{shortest-duration-space}) of space. For normal notes, this space
1771 is always counted from the left edge of the symbol, so the shortest
1772 notes are generally followed by one NHW of space.
1774 If one would follow the above procedure exactly, then adding a single
1775 32th note to a score that uses 8th and 16th notes, would widen up the
1776 entire score a lot. The shortest note is no longer a 16th, but a 32nd,
1777 thus adding 1 NHW to every note. To prevent this, the
1778 shortest duration for spacing is not the shortest note in the score,
1779 but the most commonly found shortest note. Notes that are even
1780 shorter this are followed by a space that is proportional to their
1781 duration relative to the common shortest note. So if we were to add
1782 only a few 16th notes to the example above, they would be followed by
1785 @lilypond[fragment,verbatim,relative=2]
1786 c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4
1789 The most common shortest duration is determined as follows: in every
1790 measure, the shortest duration is determined. The most common short
1791 duration, is taken as the basis for the spacing, with the stipulation
1792 that this shortest duration should always be equal to or shorter than
1793 1/8th note. The shortest duration is printed when you run lilypond
1794 with @code{--verbose}. These durations may also be customized. If you
1795 set the @code{common-shortest-duration} in
1796 @internalsref{SpacingSpanner}, then this sets the base duration for
1797 spacing. The maximum duration for this base (normally 1/8th), is set
1798 through @code{base-shortest-duration}.
1800 @cindex @code{common-shortest-duration}
1801 @cindex @code{base-shortest-duration}
1802 @cindex @code{stem-spacing-correction}
1803 @cindex @code{spacing}
1805 In the introduction it was explained that stem directions influence
1806 spacing. This is controlled with @code{stem-spacing-correction}
1807 property in @internalsref{NoteSpacing}, which are generated for every
1808 @internalsref{Voice} context. The @code{StaffSpacing} object
1809 (generated at @internalsref{Staff} context) contains the same property
1810 for controlling the stem/bar line spacing. The following example
1811 shows these corrections, once with default settings, and once with
1812 exaggerated corrections:
1818 \override Staff.NoteSpacing #'stem-spacing-correction
1820 \override Staff.StaffSpacing #'stem-spacing-correction
1825 \paper { raggedright = ##t } }
1828 @cindex SpacingSpanner, overriding properties
1830 Properties of the @internalsref{SpacingSpanner} must be overridden
1831 from the @code{\paper} block, since the @internalsref{SpacingSpanner} is
1832 created before any property commands are interpreted.
1834 \paper @{ \context @{
1836 SpacingSpanner \override #'spacing-increment = #3.0
1843 Internals: @internalsref{SpacingSpanner}, @internalsref{NoteSpacing},
1844 @internalsref{StaffSpacing}, @internalsref{SeparationItem}, and
1845 @internalsref{SeparatingGroupSpanner}.
1849 Spacing is determined on a score wide basis. If you have a score that
1850 changes its character (measured in durations) halfway during the
1851 score, the part containing the longer durations will be spaced too
1854 There is no convenient mechanism to manually override spacing.
1864 @subsection Line breaking
1867 @cindex breaking lines
1869 Line breaks are normally computed automatically. They are chosen such
1870 that lines look neither cramped nor loose, and that consecutive lines
1871 have similar density.
1873 Occasionally you might want to override the automatic breaks; you can
1874 do this by specifying @code{\break}. This will force a line break at
1875 this point. Line breaks can only occur at places where there are bar
1876 lines. If you want to have a line break where there is no bar line,
1877 you can force an invisible bar line by entering @code{\bar
1878 ""}. Similarly, @code{\noBreak} forbids a line break at a
1882 @cindex regular line breaks
1883 @cindex four bar music.
1885 For line breaks at regular intervals use @code{\break} separated by
1886 skips and repeated with @code{\repeat}:
1888 << \repeat unfold 7 @{
1889 s1 \noBreak s1 \noBreak
1890 s1 \noBreak s1 \break @}
1891 @emph{the real music}
1896 This makes the following 28 measures (assuming 4/4 time) be broken every
1897 4 measures, and only there.
1901 @code{\break}, @code{\noBreak}
1902 @cindex @code{\break}
1903 @cindex @code{\noBreak}
1907 Internals: @internalsref{BreakEvent}.
1911 @subsection Page layout
1914 @cindex breaking pages
1916 @cindex @code{indent}
1917 @cindex @code{linewidth}
1919 The most basic settings influencing the spacing are @code{indent} and
1920 @code{linewidth}. They are set in the @code{\paper} block. They
1921 control the indentation of the first line of music, and the lengths of
1924 If @code{raggedright} is set to true in the @code{\paper}
1925 block, then the lines are justified at their natural length. This
1926 useful for short fragments, and for checking how tight the natural
1930 @cindex vertical spacing
1932 The option @code{raggedlast} is similar to @code{raggedright}, but
1933 only affects the last line of the piece. No restrictions are put on
1934 that line. The result is similar to formatting paragraphs. In a
1935 paragraph, the last line simply takes its natural length.
1937 The page layout process happens outside the LilyPond formatting
1938 engine: variables controlling page layout are passed to the output,
1939 and are further interpreted by @code{lilypond} wrapper program. It
1940 responds to the following variables in the @code{\paper} block. The
1941 spacing between systems is controlled with @code{interscoreline}, its
1942 default is 16pt. The distance between the score lines will stretch in
1943 order to fill the full page @code{interscorelinefill} is set to a
1944 positive number. In that case @code{interscoreline} specifies the
1947 @cindex @code{textheight}
1948 @cindex @code{interscoreline}
1949 @cindex @code{interscorelinefill}
1951 If the variable @code{lastpagefill} is defined,
1952 @c fixme: this should only be done if lastpagefill= #t
1953 systems are evenly distributed vertically on the last page. This
1954 might produce ugly results in case there are not enough systems on the
1955 last page. The @command{lilypond-book} command ignores
1956 @code{lastpagefill}. See @ref{lilypond-book manual} for more
1959 @cindex @code{lastpagefill}
1961 Page breaks are normally computed by @TeX{}, so they are not under
1962 direct control of LilyPond. However, you can insert a commands into
1963 the @file{.tex} output to instruct @TeX{} where to break pages. This
1964 is done by setting the @code{between-systems-strings} on the
1965 @internalsref{NonMusicalPaperColumn} where the system is broken.
1966 An example is shown in @inputfileref{input/regression,between-systems.ly}.
1967 The predefined command @code{\newpage} also does this.
1971 @cindex @code{papersize}
1973 To change the paper size, there are two commands,
1975 #(set-default-paper-size "a4")
1977 #(set-paper-size "a4")
1980 The second one sets the size of the @code{\paper} block that it's in.
1984 @cindex @code{\newpage}
1990 In this manual: @ref{Invoking lilypond}.
1992 Examples: @inputfileref{input/regression,between-systems.ly}.
1994 Internals: @internalsref{NonMusicalPaperColumn}.
1998 LilyPond has no concept of page layout, which makes it difficult to
1999 reliably choose page breaks in longer pieces.
2004 @node Output details
2005 @section Output details
2007 The default output format is La@TeX{}, which should be run
2008 through La@TeX{}. Using the option @option{-f}
2009 (or @option{--format}) other output formats can be selected also, but
2010 none of them work reliably.
2012 Now the music is output system by system (a `system' consists of all
2013 staves belonging together). From @TeX{}'s point of view, a system is an
2014 @code{\hbox} which contains a lowered @code{\vbox} so that it is centered
2015 vertically on the baseline of the text. Between systems,
2016 @code{\interscoreline} is inserted vertically to have stretchable space.
2017 The horizontal dimension of the @code{\hbox} is given by the
2018 @code{linewidth} parameter from LilyPond's @code{\paper} block.
2020 After the last system LilyPond emits a stronger variant of
2021 @code{\interscoreline} only if the macro
2022 @code{\lilypondpaperlastpagefill} is not defined (flushing the systems
2023 to the top of the page). You can avoid that by setting the variable
2024 @code{lastpagefill} in LilyPond's @code{\paper} block.
2026 It is possible to fine-tune the vertical offset further by defining the
2027 macro @code{\lilypondscoreshift}:
2030 \def\lilypondscoreshift@{0.25\baselineskip@}
2034 where @code{\baselineskip} is the distance from one text line to the next.
2036 Here an example how to embed a small LilyPond file @code{foo.ly} into
2037 running La@TeX{} text without using the @code{lilypond-book} script
2038 (@pxref{lilypond-book manual}):
2041 \documentclass@{article@}
2043 \def\lilypondpaperlastpagefill@{@}
2045 \def\lilypondscoreshift@{0.25\baselineskip@}
2048 This is running text which includes an example music file
2054 The file @file{foo.tex} has been simply produced with
2060 The call to @code{\lineskip} assures that there is enough vertical space
2061 between the LilyPond box and the surrounding text lines.