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 this 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 explains how to lookup which knob to use for a
14 The controls 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 written 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 LilyPond 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 notation elements must be added to the
236 input, which is often bare bones. For example, compare the input and
237 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. This information can be presented on
249 several levels. For example, the effect of an accidental is limited
250 to a single stave, while a bar line must be synchronized across the
253 Within LilyPond, these rules and bits of information are grouped in
254 so-called Contexts. Examples of context are @context{Voice},
255 @context{Staff}, and @context{Score}. They are hierarchical, for
256 example, a @context{Staff} can contain many @context{Voice}s, and a
257 @context{Score} can contain many @context{Staff} contexts.
259 Each context has the responsibility for enforcing some notation rules,
260 creating some notation objects and maintaining the associated
261 properties. So, the synchronization of bar lines is handled at
262 @context{Score} context. The @context{Voice} may introduce an
263 accidentals and then the @context{Staff} context maintains the rule to
264 show or suppress the accidental for the remainder of the measure.
266 For simple scores, contexts are created implicitly, and you need not
267 be aware of them. For larger pieces, such as piano music, they must be
268 created explicitly to make sure that you get as many staves as you
269 need, and that they are in the correct order. For typesetting pieces
270 with specialized notation, it can be useful to modify existing or
274 Full description of all available contexts is in the program
277 @internalsref{Contexts}.
280 Translation @arrow{} Context.
283 @c [TODO: describe propagation]
287 * Creating contexts::
288 * Changing context properties on the fly ::
289 * Modifying context plug-ins::
290 * Layout tunings within contexts::
291 * Changing context default settings::
292 * Defining new contexts::
293 * Which properties to change::
296 @node Creating contexts
297 @subsection Creating contexts
299 For scores with only one voice and one staff, correct contexts are
300 created automatically. For more complex scores, it is necessary to
301 create them by hand. There are three commands which 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 @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[verbatim,relative=2,raggedright]
324 << \new Staff { c4 c }
329 @cindex @code{\context}
331 Like @code{\new}, the @code{\context} command also directs a music
332 expression to a context object, but gives the context an extra name. The
336 \context @var{type} = @var{id} @var{music}
339 This form will search for an existing context of type @var{type}
340 called @var{id}. If that context does not exist yet, it is created.
341 This is useful if the context is referred to later on. For example, when
342 setting lyrics the melody is in a named context
345 \context Voice = "@b{tenor}" @var{music}
349 so the texts can be properly aligned to its notes,
352 \new Lyrics \lyricsto "@b{tenor}" @var{lyrics}
357 Another possibility is funneling two different music expressions into
358 one context. In the following example, articulations and notes are
362 music = \notes { c4 c4 }
363 arts = \notes { s4-. s4-> }
366 They are combined by sending both to the same @context{Voice} context,
369 << \new Staff \context Voice = "A" \music
370 \context Voice = "A" \arts
373 @lilypond[raggedright]
374 music = \notes { c4 c4 }
375 arts = \notes { s4-. s4-> }
377 \notes \relative c'' << \new Staff \context Voice = "A" \music
378 \context Voice = "A" \arts
383 @cindex @code{\context}
384 @cindex creating contexts
386 The third command for creating contexts is
388 \context @var{type} @var{music}
393 This is similar to @code{\context} with @code{= @var{id}}, but matches
394 any context of type @var{type}, regardless of its given name.
396 This variant is used with music expressions that can be interpreted at
397 several levels. For example, the @code{\applyoutput} command (see
398 @ref{Running a function on all layout objects}). Without an explicit
399 @code{\context}, it is usually is applied to @context{Voice}
402 \applyoutput #@var{function} % apply to Voice
405 To have it interpreted at the @context{Score} or @context{Staff} level use
409 \context Score \applyoutput #@var{function}
410 \context Staff \applyoutput #@var{function}
414 @node Changing context properties on the fly
415 @subsection Changing context properties on the fly
419 @cindex changing properties
421 Each context can have different @emph{properties}, variables contained
422 in that context. They can be changed during the interpretation step.
423 This is achieved by inserting the @code{\set} command in the music,
426 @code{\set } @var{context}@code{.}@var{prop}@code{ = #}@var{value}
430 @lilypond[verbatim,relative=2]
432 \set Score.skipBars = ##t
436 This command skips measures that have no notes. The result is that
437 multi rests are condensed. The value assigned is a Scheme object. In
438 this case, it is @code{#t}, the boolean True value.
440 If the @var{context} argument is left out, then the current bottom-most
441 context (typically @context{ChordNames}, @context{Voice}, or
442 @context{Lyrics}) is used. In this example,
444 @lilypond[verbatim,relative=2]
446 \set autoBeaming = ##f
451 the @var{context} argument to @code{\set} is left out, and the current
452 @internalsref{Voice} is used.
454 Contexts are hierarchical, so if a bigger context was specified, for
455 example @context{Staff}, then the change would also apply to all
456 @context{Voice}s in the current stave. The change is applied
457 `on-the-fly', during the music, so that the setting only affects the
458 second group of eighth notes.
460 @cindex @code{\unset}
462 There is also an @code{\unset} command,
464 @code{\set }@var{context}@code{.}@var{prop}
468 which removes the definition of @var{prop}. This command removes
469 the definition only if it is set in @var{context}. In
472 \set Staff.autoBeaming = ##f
473 \unset Voice.autoBeaming
477 the current @context{Voice} does not have the property, and the
478 definition at @context{Staff} level remains intact. Like @code{\set},
479 the @var{context} argument does not have to be specified for a bottom
482 Settings that should only apply to a single time-step can be entered
483 easily with @code{\once}, for example in
485 @lilypond[verbatim,relative=2]
487 \once \set fontSize = #4.7
492 the property @code{fontSize} is unset automatically after the second
495 A full description of all available context properties is in the
496 program reference, see
498 @internalsref{Tunable-context-properties}.
501 Translation @arrow{} Tunable context properties.
505 @node Modifying context plug-ins
506 @subsection Modifying context plug-ins
508 Notation contexts (like Score and Staff) not only store properties,
509 they also contain plug-ins, called ``engravers'' that create notation
510 elements. For example, the Voice context contains a
511 @code{Note_head_engraver} and the Staff context contains a
512 @code{Key_signature_engraver}.
514 For a full a description of each plug-in, see
516 @internalsref{Engravers}.
519 Program reference @arrow Translation @arrow{} Engravers.
521 Every context described in
523 @internalsref{Contexts}
526 Program reference @arrow Translation @arrow{} Context.
528 lists the engravers used for that context.
531 It can be useful to shuffle around these plug-ins. This is done by
532 starting a new context, with @code{\new} or @code{\context}, and
533 modifying it like this,
536 \new @var{context} \with @{
546 where the @dots{} should be the name of an engraver. Here is a simple
547 example which removes @code{Time_signature_engraver} and
548 @code{Clef_engraver} from a @code{Staff} context,
550 @lilypond[relative=1, verbatim]
555 \remove "Time_signature_engraver"
556 \remove "Clef_engraver"
563 In the second stave there are no time signature or clef symbols. This
564 is a rather crude method of making objects disappear since it will affect
565 the entire staff. The spacing will be adversely influenced too. A more
566 sophisticated methods of blanking objects is shown in @ref{Common
569 The next example shows a practical application. Bar lines and time
570 signatures are normally synchronized across the score. This is done
571 by the @code{Timing_engraver}. This plug-in keeps an administration of
572 time signature, location within the measure, etc. By moving the
573 @code{Timing_engraver} engraver from Score to Staff context, we can
574 have a score where each staff has its own time signature.
576 @cindex polymetric scores
579 @lilypond[relative=1,raggedright,verbatim]
581 \remove "Timing_engraver"
584 \consists "Timing_engraver"
590 \consists "Timing_engraver"
599 @node Layout tunings within contexts
600 @subsection Layout tunings within contexts
602 Each context is responsible for creating certain types of graphical
603 objects. The settings used for printing these objects are also stored by
604 context. By changing these settings, the appearance of objects can be
607 The syntax for this is
610 \override @var{context}.@var{name}@code{ #'}@var{property} = #@var{value}
613 Here @var{name} is the name of a graphical object, like @code{Stem} or
614 @code{NoteHead}, and @var{property} is an internal variable of the
615 formatting system (`grob property' or `layout property'). The latter is a
616 symbol, so it must be quoted. The subsection @ref{Constructing a
617 tweak} explains what to fill in for @var{name}, @var{property}, and
618 @var{value}. Here we only discuss functionality of this command.
623 \override Staff.Stem #'thickness = #4.0
627 makes stems thicker (the default is 1.3, with staff line thickness as a
628 unit). Since the command specifies @context{Staff} as context, it only
629 applies to the current staff. Other staves will keep their normal
630 appearance. Here we see the command in action:
632 @lilypond[verbatim,relative=2]
634 \override Staff.Stem #'thickness = #4.0
640 The @code{\override} command is executed during the interpreting phase,
641 and changes the definition of the @code{Stem} within
642 @context{Staff}. After the command all stems are thickened.
644 Analogous to @code{\set}, the @var{context} argument may be left out,
645 causing it to default to @context{Voice}, and adding @code{\once} applies
646 the change during one timestep only
648 @lilypond[verbatim,relative=2]
650 \once \override Stem #'thickness = #4.0
655 The @code{\override} must be done before the object is
656 started. Therefore, when altering @emph{Spanner} objects, like slurs or
657 beams, the @code{\override} command must be executed at the moment when
658 the object is created. In this example,
661 @lilypond[verbatim,relative=2]
662 \override Slur #'thickness = #3.0
664 \override Beam #'thickness = #0.6
669 the slur is fatter and the beam is not. This is because the command for
670 @code{Beam} comes after the Beam is started. Therefore it has no effect.
672 Analogous to @code{\unset}, the @code{\revert} command for a context
673 undoes a @code{\override} command; like with @code{\unset}, it only
674 affects settings that were made in the same context. In other words, the
675 @code{\revert} in the next example does not do anything.
678 \override Voice.Stem #'thickness = #4.0
679 \revert Staff.Stem #'thickness
687 Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
688 @internalsref{PropertySet}, @internalsref{All-backend-properties}, and
689 @internalsref{All-layout-objects}.
694 The back-end is not very strict in type-checking object properties.
695 Cyclic references in Scheme values for properties can cause hangs
699 @node Changing context default settings
700 @subsection Changing context default settings
702 The adjustments of the previous chapters can also be entered separate
703 from the music, in the @code{\paper} block,
712 \override Stem #'thickness
713 \remove "Time_signature_engraver"
724 takes the existing definition @context{Staff} from the identifier
725 @code{Staff}. This works analogously to other contexts.
730 \override Stem #'thickness
731 \remove "Time_signature_engraver"
735 affect all staves in the score.
737 The @code{\set} keyword is optional within the @code{\paper} block, so
750 It is not possible to collect changes in a variable, and apply them to
751 one @code{\context} definition by referring to that variable.
754 @node Defining new contexts
755 @subsection Defining new contexts
757 Specific contexts, like @context{Staff} and @code{Voice}, are made of
758 simple building blocks, and it is possible to compose engraver
759 plug-ins in different combinations, thereby creating new types of
762 The next example shows how to build a different type of
763 @context{Voice} context from scratch. It will be similar to
764 @code{Voice}, but print centered slash noteheads only. It can be used
765 to indicate improvisation in Jazz pieces,
767 @lilypond[raggedright]
770 \type "Engraver_group_engraver"
771 \consists "Note_heads_engraver"
772 \consists "Text_engraver"
773 \consists Pitch_squash_engraver
774 squashedPosition = #0
775 \override NoteHead #'style = #'slash
776 \override Stem #'transparent = ##t
780 \accepts "ImproVoice"
782 \score { \notes \relative c'' {
783 a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
784 c4 c^"undress" c_"while playing :)" c }
790 These settings are again done within a @code{\context} block inside a
801 In the following discussion, the example input shown should go on the
802 @dots{} in the previous fragment.
804 First, name the context gets a name. Instead of @context{Voice} it
805 will be called @context{ImproVoice},
811 Since it is similar to the @context{Voice}, we want commands that work
812 on (existing) @context{Voice}s to remain working. This is achieved by
813 giving the new context an alias @context{Voice},
819 The context will print notes, and instructive texts
822 \consists Note_heads_engraver
823 \consists Text_engraver
826 but only on the center line,
829 \consists Pitch_squash_engraver
830 squashedPosition = #0
833 The @internalsref{Pitch_squash_engraver} modifies note heads (created
834 by @internalsref{Note_heads_engraver}) and sets their vertical
835 position to the value of @code{squashedPosition}, in this case
836 @code{0}, the center line.
838 The notes look like a slash, without a stem,
841 \override NoteHead #'style = #'slash
842 \override Stem #'transparent = ##t
846 All these plug-ins have to cooperate, and this is achieved with a
847 special plug-in, which must be marked with the keyword @code{\type}.
848 This should always be @internalsref{Engraver_group_engraver},
851 \type "Engraver_group_engraver"
854 Putting together, we get
859 \type "Engraver_group_engraver"
860 \consists "Note_heads_engraver"
861 \consists "Text_script_engraver"
862 \consists Pitch_squash_engraver
863 squashedPosition = #0
864 \override NoteHead #'style = #'slash
865 \override Stem #'transparent = ##t
870 Contexts form hierarchies. We want to hang the @context{ImproVoice}
871 under @context{Staff}, just like normal @code{Voice}s. Therefore, we
872 modify the @code{Staff} definition with the @code{\accepts}
873 command,@footnote{The opposite of @code{\accepts} is @code{\denies},
874 which is sometimes when reusing existing context definitions. }
885 Putting both into a @code{\paper} block, like
895 \accepts "ImproVoice"
900 Then the output at the start of this subsection can be entered as
904 \notes \relative c'' {
909 c c_"while playing :)"
918 @node Which properties to change
919 @subsection Which properties to change
922 There are many different properties. Not all of them are listed in
923 this manual. However, the program reference lists them all in the
924 section @internalsref{Tunable-context-properties}, and most properties
925 are demonstrated in one of the
927 @uref{../../../../input/test/out-www/collated-files.html,tips-and-tricks}
936 @section Tuning output
938 In the previous section, we have already touched on a command that
939 changes layout details, the @code{\override} command. In this section,
940 we will look at in more detail how to use the command in practice.
941 First, we will give a a few versatile commands, which are sufficient
942 for many situations. The next section will discuss general use of
946 There are situations where default layout decisions are not
947 sufficient. In this section we discuss ways to override these
950 Formatting is internally done by manipulating so called objects
951 (graphic objects). Each object carries with it a set of properties
952 (object or layout properties) specific to the object. For example, a
953 stem object has properties that specify its direction, length, and
956 The most direct way of tuning the output is to alter the values of
957 these properties. There are two ways of doing that: First, you can
958 temporarily change the definition of one type of object, thus
959 affecting a whole set of objects. Second, you can select one specific
960 object, and set a layout property in that object.
962 Do not confuse layout properties with translation
963 properties. Translation properties always use a mixed caps style
964 naming, and are manipulated using @code{\set} and @code{\unset}:
966 \set Context.propertyName = @var{value}
969 Layout properties are use Scheme style variable naming, i.e. lower
970 case words separated with dashes. They are symbols, and should always
971 be quoted using @code{#'}. For example, this could be an imaginary
972 layout property name:
974 #'layout-property-name
981 * Constructing a tweak::
982 * Navigating the program reference::
983 * Layout interfaces::
984 * Determining the grob property::
990 @subsection Common tweaks
992 Some overrides are so common that predefined commands are provided as
993 a short-cut, for example, @code{\slurUp} and @code{\stemDown}. These
994 commands are described in
998 @ref{Notation manual}, under the sections for slurs and stems
1001 The exact tuning possibilities for each type of layout object are
1002 documented in the program reference of the respective
1003 object. However, many layout objects share properties, which can be
1004 used to apply generic tweaks. We mention a few of these:
1007 @item The @code{extra-offset} property, which
1008 @cindex @code{extra-offset}
1009 has a pair of numbers as value, moves around objects in the printout.
1010 The first number controls left-right movement; a positive number will
1011 move the object to the right. The second number controls up-down
1012 movement; a positive number will move it higher. The units of these
1013 offsets are staff-spaces. The @code{extra-offset} property is a
1014 low-level feature: the formatting engine is completely oblivious to
1017 In the following example, the second fingering is moved a little to
1018 the left, and 1.8 staff space downwards:
1020 @cindex setting object properties
1022 @lilypond[relative=1,verbatim]
1025 \once \override Fingering
1026 #'extra-offset = #'(-0.3 . -1.8)
1031 Setting the @code{transparent} property will cause an object to be printed
1032 in `invisible ink': the object is not printed, but all its other
1033 behavior is retained. The object still takes up space, it takes part in
1034 collisions, and slurs, and ties and beams can be attached to it.
1036 @cindex transparent objects
1037 @cindex removing objects
1038 @cindex hiding objects
1039 @cindex invisible objects
1040 The following example demonstrates how to connect different voices
1041 using ties. Normally, ties only connect two notes in the same
1042 voice. By introducing a tie in a different voice,
1044 @lilypond[fragment,relative=2]
1053 and blanking a stem in that voice, the tie appears to cross voices:
1055 @lilypond[fragment,relative=2,verbatim]
1057 \once \override Stem #'transparent = ##t
1065 The @code{padding} property for objects with
1066 @cindex @code{padding}
1067 @code{side-position-interface} can be set to increase distance between
1068 symbols that are printed above or below notes. We only give an
1069 example; a more elaborate explanation is in @ref{Constructing a
1072 @lilypond[relative=1,verbatim]
1074 \override Script #'padding = #3
1080 More specific overrides are also possible. The next section
1081 discusses in depth how to figure out these statements for yourself.
1084 @node Constructing a tweak
1085 @subsection Constructing a tweak
1087 The general procedure of changing output, that is, entering
1091 \override Voice.Stem #'thickness = #3.0
1095 means that we have to determine these bits of information:
1098 @item the context: here @context{Voice}.
1099 @item the layout object: here @code{Stem}.
1100 @item the layout property: here @code{thickness}
1101 @item a sensible value: here @code{3.0}
1105 @cindex internal documentation
1106 @cindex finding graphical objects
1107 @cindex graphical object descriptions
1109 @cindex @code{\override}
1111 @cindex internal documentation
1113 We demonstrate how to glean this information from the notation manual
1114 and the program reference.
1116 The program reference is a set of HTML pages, which is part of the
1117 documentation package. On Unix systems, it is typically in
1118 @file{/usr/share/doc/lilypond}. If you have them, it is best to
1119 bookmark them in your webbrowser, because you will need them. They
1120 are also available on the web: go to the
1121 @uref{http://lilypond.org,LilyPond website}, click ``Documentation'',
1122 select the correct version, and then click ``Program reference.''
1124 If you have them, use the local HTML files. They will load faster,
1125 and they are exactly matched to LilyPond version installed.
1128 @node Navigating the program reference
1129 @subsection Navigating the program reference
1131 Suppose we want to move the fingering indication in the fragment
1134 @lilypond[relative=2,verbatim]
1140 If you visit the documentation of @code{Fingering} (in @ref{Fingering
1141 instructions}), you will notice that there is written:
1146 Program reference: @internalsref{FingerEvent} and @internalsref{Fingering}.
1150 This fragments points to two parts of the program reference: a page
1151 on @code{FingerEvent} and on @code{Fingering}.
1153 The page on @code{FingerEvent} describes the properties of the music
1154 expression for the input @code{-2}. The page contains many links
1155 forward. For example, it says
1158 Accepted by: @internalsref{Fingering_engraver},
1162 That link brings us to the documentation for the Engraver, the
1166 This engraver creates the following layout objects: @internalsref{Fingering}.
1169 In other words, once the @code{FingerEvent}s are interpreted, the
1170 @code{Fingering_engraver} plug-in will process them.
1171 The @code{Fingering_engraver} is also listed to create
1172 @internalsref{Fingering} objects,
1175 Lo and behold, that is also the
1176 second bit of information listed under @b{See also} in the Notation
1177 manual. By clicking around in the program reference, we can follow the
1178 flow of information within the program, either forward (like we did
1179 here), or backwards, following links like this:
1183 @item @internalsref{Fingering}:
1184 @internalsref{Fingering} objects are created by:
1185 @b{@internalsref{Fingering_engraver}}
1187 @item @internalsref{Fingering_engraver}:
1188 Music types accepted: @b{@internalsref{fingering-event}}
1189 @item @internalsref{fingering-event}:
1190 Music event type @code{fingering-event} is in Music objects of type
1191 @b{@internalsref{FingerEvent}}
1194 This path goes against the flow of information in the program: it
1195 starts from the output, and ends at the input event.
1197 The program reference can also be browsed like a normal document. It
1198 contains a chapter on
1200 @internalsref{Music-definitions},
1205 on @internalsref{Translation}, and the @internalsref{Backend}. Every
1206 chapter lists all the definitions used, and all properties that may be
1210 @node Layout interfaces
1211 @subsection Layout interfaces
1213 @internalsref{Fingering} is a layout object. Such an object is a
1214 symbol within the score. It has properties, which store numbers (like
1215 thicknesses and directions), but also pointers to related objects.
1216 A layout object is also called @emph{grob},
1218 which is short for Graphical Object.
1221 The page for @code{Fingering} lists the definitions for the
1222 @code{Fingering} object. For example, the page says
1225 @code{padding} (dimension, in staff space):
1230 which means that the number will be kept at a distance of at least 0.6
1234 Each layout object may have several functions as a notational or
1235 typographical element. For example, the Fingering object
1236 has the following aspects
1239 @item Its size is independent of the horizontal spacing, unlike slurs or beams
1241 @item It is a piece of text. Granted, it's usually a very short text.
1243 @item That piece of text is typeset with a font, unlike slurs or beams.
1244 @item Horizontally, the center of the symbol should be aligned to the
1245 center of the notehead
1246 @item Vertically, the symbol is placed next to the note and the staff.
1249 vertical position is also coordinated with other super and subscript
1253 Each of these aspects is captured in a so-called @emph{interface},
1254 which are listed on the @internalsref{Fingering} page at the bottom
1257 This object supports the following interfaces:
1258 @internalsref{item-interface},
1259 @internalsref{self-alignment-interface},
1260 @internalsref{side-position-interface}, @internalsref{text-interface},
1261 @internalsref{text-script-interface}, @internalsref{font-interface},
1262 @internalsref{finger-interface}, and @internalsref{grob-interface}.
1265 Clicking any of the links will take you to the page of the respective
1266 object interface. Each interface has a number of properties. Some of
1267 them are not user-serviceable (``Internal properties''), but others
1270 We have been talking of `the' @code{Fingering} object, but actually it
1271 does not amount to much. The initialization file
1272 @file{scm/define-grobs.scm} shows the soul of the `object',
1277 (print-function . ,Text_item::print)
1279 (staff-padding . 0.6)
1280 (self-alignment-X . 0)
1281 (self-alignment-Y . 0)
1282 (script-priority . 100)
1283 (font-encoding . number)
1285 (meta . ((interfaces . (finger-interface font-interface
1286 text-script-interface text-interface
1287 side-position-interface self-alignment-interface
1292 as you can see, @code{Fingering} is nothing more than a bunch of
1293 variable settings, and the webpage is directly generated from this
1296 @node Determining the grob property
1297 @subsection Determining the grob property
1300 Recall that we wanted to change the position of the @b{2} in
1302 @lilypond[relative=2,verbatim]
1308 Since the @b{2} is vertically positioned next to its note, we have to
1309 meddle with the interface associated with this positioning. This is
1310 done using @code{side-position-interface}. The page for this interface
1314 @code{side-position-interface}
1316 Position a victim object (this one) next to other objects (the
1317 support). The property @code{direction} signifies where to put the
1318 victim object relative to the support (left or right, up or down?)
1323 below this description, the variable @code{padding} is described as
1327 (dimension, in staff space)
1329 add this much extra space between objects that are next to each
1334 By increasing the value of @code{padding}, we can move away the
1335 fingering. The following command inserts 3 staff spaces of white
1336 between the note and the fingering:
1338 \once \override Fingering #'padding = #3
1341 Inserting this command before the Fingering object is created,
1342 i.e. before @code{c2}, yields the following result:
1344 @lilypond[relative=2,fragment,verbatim]
1345 \once \override Fingering
1353 In this case, the context for this tweak is @context{Voice}, which
1354 does not have to be specified for @code{\override}. This fact can
1355 also be deduced from the program reference, for the page for the
1356 @internalsref{Fingering_engraver} plug-in says
1359 Fingering_engraver is part of contexts: @dots{} @b{@internalsref{Voice}}
1367 * Selecting font sizes::
1373 @node Selecting font sizes
1374 @subsection Selecting font sizes
1376 The most common thing to change about the appearance of fonts is their
1377 size. The font size of any context can be easily changed by setting
1378 the @code{fontSize} property for that context. Its value is a number:
1379 negative numbers make the font smaller, positive numbers larger. An
1380 example is given below:
1382 @lilypond[fragment,relative=1,verbatim]
1383 c4 c4 \set fontSize = #-3
1386 This command will set @code{font-size} (see below) in all layout
1387 objects in the current context. It does not change the size of
1388 variable symbols, such as beams or slurs.
1390 The font size is set by modifying the @code{font-size} property. Its
1391 value is a number indicating the size relative to the standard size.
1392 Each step up is an increase of approximately 12% of the font size. Six
1393 steps is exactly a factor two. The Scheme function @code{magstep}
1394 converts a @code{font-size} number to a scaling factor.
1396 LilyPond has fonts in different design sizes: the music fonts for
1397 smaller sizes are chubbier, while the text fonts are relatively wider.
1398 Font size changes are achieved by scaling the design size that is
1399 closest to the desired size.
1401 The @code{font-size} mechanism does not work for fonts selected
1402 through @code{font-name}. These may be scaled with
1403 @code{font-magnification}.
1406 One of the uses of @code{fontSize} is to get smaller symbols for cue
1407 notes. An elaborate example of those is in
1408 @inputfileref{input/test,cue-notes.ly}.
1411 @cindex @code{font-style}
1415 The following commands set @code{fontSize} for the current voice:
1417 @cindex @code{\tiny}
1419 @cindex @code{\small}
1421 @cindex @code{\normalsize}
1426 @cindex magnification
1430 @node Font selection
1431 @subsection Font selection
1433 Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
1434 can also be adjusted with a more fine-grained mechanism. By setting
1435 the object properties described below, you can select a different font;
1436 all three mechanisms work for every object that supports
1437 @code{font-interface}:
1441 @item @code{font-encoding}
1442 is a symbol that sets layout of the glyphs. Choices include
1443 @code{text} for normal text, @code{braces} (for piano staff braces),
1444 @code{music} (the standard music font, including ancient glyphs),
1445 @code{dynamic} (for dynamic signs) and @code{number} for the number
1449 @item @code{font-family}
1450 is a symbol indicating the general class of the typeface. Supported are
1451 @code{roman} (Computer Modern), @code{sans}, and @code{typewriter}.
1453 @item @code{font-shape}
1454 is a symbol indicating the shape of the font, there are typically
1455 several font shapes available for each font family. Choices are
1456 @code{italic}, @code{caps}, and @code{upright}.
1458 @item @code{font-series}
1459 is a symbol indicating the series of the font. There are typically several
1460 font series for each font family and shape. Choices are @code{medium}
1465 Fonts selected in the way sketched above come from a predefined style
1468 The font used for printing a object can be selected by setting
1469 @code{font-name}, e.g.
1471 \override Staff.TimeSignature
1472 #'font-name = #"cmr17"
1476 Any font can be used, as long as it is available to @TeX{}. Possible
1477 fonts include foreign fonts or fonts that do not belong to the
1478 Computer Modern font family. The size of fonts selected in this way
1479 can be changed with the @code{font-magnification} property. For
1480 example, @code{2.0} blows up all letters by a factor 2 in both
1484 @cindex font magnification
1490 Init files: @file{ly/declarations-init.ly} contains hints how new
1491 fonts may be added to LilyPond.
1495 No style sheet is provided for other fonts besides the @TeX{}
1496 Computer Modern family.
1498 @cindex font selection
1499 @cindex font magnification
1500 @cindex @code{font-interface}
1504 @section Text markup
1509 @cindex typeset text
1511 LilyPond has an internal mechanism to typeset texts. You can access it
1512 with the keyword @code{\markup}. Within markup mode, you can enter texts
1513 similar to lyrics: simply enter them, surrounded by spaces:
1516 @lilypond[verbatim,fragment,relative=1]
1517 c1^\markup { hello }
1518 c1_\markup { hi there }
1519 c1^\markup { hi \bold there, is \italic anyone home? }
1522 @cindex font switching
1524 The markup in the example demonstrates font switching commands. The
1525 command @code{\bold} and @code{\italic} apply to the first following
1526 word only; enclose a set of texts with braces to apply a command
1529 \markup @{ \bold @{ hi there @} @}
1533 For clarity, you can also do this for single arguments, e.g.
1536 \markup { is \italic { anyone } home }
1539 @cindex font size, texts
1542 In markup mode you can compose expressions, similar to mathematical
1543 expressions, XML documents, and music expressions. The braces group
1544 notes into horizontal lines. Other types of lists also exist: you can
1545 stack expressions grouped with @code{<} and @code{>} vertically with
1546 the command @code{\column}. Similarly, @code{\center-align} aligns
1547 texts by their center lines:
1549 @lilypond[verbatim,fragment,relative=1]
1550 c1^\markup { \column < a bbbb c > }
1551 c1^\markup { \center-align < a bbbb c > }
1552 c1^\markup { \line < a b c > }
1556 Markups can be stored in variables, and these variables
1557 may be attached to notes, like
1559 allegro = \markup { \bold \large { Allegro } }
1560 \notes { a^\allegro b c d }
1564 Some objects have alignment procedures of their own, which cancel out
1565 any effects of alignments applied to their markup arguments as a
1566 whole. For example, the @internalsref{RehearsalMark} is horizontally
1567 centered, so using @code{\mark \markup @{ \left-align .. @}} has no
1570 Similarly, for moving whole texts over notes with
1571 @code{\raise}, use the following trick:
1573 "" \raise #0.5 raised
1576 The text @code{raised} is now raised relative to the empty string
1577 @code{""} which is not visible. Alternatively, complete objects can
1578 be moved with layout properties such as @code{padding} and
1579 @code{extra-offset}.
1585 Init files: @file{scm/new-markup.scm}.
1590 Text layout is ultimately done by @TeX{}, which does kerning of
1591 letters. LilyPond does not account for kerning, so texts will be
1592 spaced slightly too wide.
1594 Syntax errors for markup mode are confusing.
1596 Markup texts cannot be used in the titling of the @code{\header}
1597 field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
1603 * Overview of text markup commands::
1606 @node Overview of text markup commands
1607 @subsection Overview of text markup commands
1609 @include markup-commands.tely
1613 @section Global layout
1615 The global layout determined by three factors: the page layout, the
1616 line breaks, and the spacing. These all influence each other. The
1617 choice of spacing determines how densely each system of music is set,
1618 which influences where line breaks are chosen, and thus
1619 ultimately how many pages a piece of music takes. This section
1620 explains how to tune the algorithm for spacing.
1622 Globally spoken, this procedure happens in three steps: first,
1623 flexible distances (``springs'') are chosen, based on durations. All
1624 possible line breaking combination are tried, and the one with the
1625 best results --- a layout that has uniform density and requires as
1626 little stretching or cramping as possible --- is chosen. When the score
1627 is processed by @TeX{}, each page is filled with systems, and page breaks
1628 are chosen whenever the page gets full.
1633 * Setting global staff size::
1634 * Vertical spacing::
1635 * Horizontal spacing::
1641 @node Setting global staff size
1642 @subsection Setting global staff size
1644 @cindex font size, setting
1645 @cindex staff size, setting
1646 @cindex @code{paper} file
1648 The Feta font provides musical symbols at eight different
1649 sizes. Each font is tuned for a different staff size: at a smaller size
1650 the font becomes heavier, to match the relatively heavier staff lines.
1651 The recommended font sizes are listed in the following table:
1653 @multitable @columnfractions .25 .25 .25 .25
1656 @tab @b{staff height (pt)}
1657 @tab @b{staff height (mm)}
1699 @c modern rental material ?
1703 These fonts are available in any sizes. The context property
1704 @code{fontSize} and the layout property @code{staff-space} (in
1705 @internalsref{StaffSymbol}) can be used to tune size for individual
1706 staves. The size of individual staves are relative to the global size,
1707 which can be set in the following manner:
1710 #(set-global-staff-size 14)
1713 This sets the global default size to 14pt staff height, and scales all
1718 This manual: @ref{Selecting font sizes}.
1723 * Vertical spacing::
1724 * Horizontal spacing::
1729 @node Vertical spacing
1730 @subsection Vertical spacing
1732 @cindex vertical spacing
1733 @cindex distance between staves
1734 @cindex staff distance
1735 @cindex between staves, distance
1736 @cindex staves per page
1737 @cindex space between staves
1739 The height of each system is determined automatically by LilyPond, to
1740 keep systems from bumping into each other, some minimum distances are
1741 set. By changing these, you can put staves closer together, and thus
1742 put more systems onto one page.
1744 Normally staves are stacked vertically. To make
1745 staves maintain a distance, their vertical size is padded. This is
1746 done with the property @code{minimumVerticalExtent}. It takes a pair
1747 of numbers, so if you want to make it smaller from its, then you could
1750 \set Staff.minimumVerticalExtent = #'(-4 . 4)
1752 This sets the vertical size of the current staff to 4 staff spaces on
1753 either side of the center staff line. The argument of
1754 @code{minimumVerticalExtent} is interpreted as an interval, where the
1755 center line is the 0, so the first number is generally negative. The
1756 staff can be made larger at the bottom by setting it to @code{(-6
1759 The piano staves are handled a little differently: to make cross-staff
1760 beaming work correctly, it is necessary that the distance between staves
1761 is fixed beforehand. This is also done with a
1762 @internalsref{VerticalAlignment} object, created in
1763 @internalsref{PianoStaff}. In this object the distance between the
1764 staves is fixed by setting @code{forced-distance}. If you want to
1765 override this, use a @code{\context} block as follows:
1770 \override VerticalAlignment #'forced-distance = #9
1775 This would bring the staves together at a distance of 9 staff spaces,
1776 measured from the center line of each staff.
1780 Internals: Vertical alignment of staves is handled by the
1781 @internalsref{VerticalAlignment} object.
1786 @node Horizontal spacing
1787 @subsection Horizontal Spacing
1789 The spacing engine translates differences in durations into
1790 stretchable distances (``springs'') of differing lengths. Longer
1791 durations get more space, shorter durations get less. The shortest
1792 durations get a fixed amount of space (which is controlled by
1793 @code{shortest-duration-space} in the @internalsref{SpacingSpanner} object).
1794 The longer the duration, the more space it gets: doubling a
1795 duration adds a fixed amount (this amount is controlled by
1796 @code{spacing-increment}) of space to the note.
1798 For example, the following piece contains lots of half, quarter, and
1799 8th notes, the eighth note is followed by 1 note head width (NHW).
1800 The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
1801 @lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8
1805 Normally, @code{shortest-duration-space} is set to 1.2, which is the
1806 width of a note head, and @code{shortest-duration-space} is set to
1807 2.0, meaning that the shortest note gets 2 NHW (i.e. 2 times
1808 @code{shortest-duration-space}) of space. For normal notes, this space
1809 is always counted from the left edge of the symbol, so the shortest
1810 notes are generally followed by one NHW of space.
1812 If one would follow the above procedure exactly, then adding a single
1813 32th note to a score that uses 8th and 16th notes, would widen up the
1814 entire score a lot. The shortest note is no longer a 16th, but a 32nd,
1815 thus adding 1 NHW to every note. To prevent this, the
1816 shortest duration for spacing is not the shortest note in the score,
1817 but the most commonly found shortest note. Notes that are even
1818 shorter this are followed by a space that is proportional to their
1819 duration relative to the common shortest note. So if we were to add
1820 only a few 16th notes to the example above, they would be followed by
1823 @lilypond[fragment,verbatim,relative=2]
1824 c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4
1827 The most common shortest duration is determined as follows: in every
1828 measure, the shortest duration is determined. The most common short
1829 duration, is taken as the basis for the spacing, with the stipulation
1830 that this shortest duration should always be equal to or shorter than
1831 1/8th note. The shortest duration is printed when you run lilypond
1832 with @code{--verbose}. These durations may also be customized. If you
1833 set the @code{common-shortest-duration} in
1834 @internalsref{SpacingSpanner}, then this sets the base duration for
1835 spacing. The maximum duration for this base (normally 1/8th), is set
1836 through @code{base-shortest-duration}.
1838 @cindex @code{common-shortest-duration}
1839 @cindex @code{base-shortest-duration}
1840 @cindex @code{stem-spacing-correction}
1841 @cindex @code{spacing}
1843 In the Introduction it was explained that stem directions influence
1844 spacing. This is controlled with @code{stem-spacing-correction}
1845 property in @internalsref{NoteSpacing}, which are generated for every
1846 @internalsref{Voice} context. The @code{StaffSpacing} object
1847 (generated at @internalsref{Staff} context) contains the same property
1848 for controlling the stem/bar line spacing. The following example
1849 shows these corrections, once with default settings, and once with
1850 exaggerated corrections:
1856 \override Staff.NoteSpacing #'stem-spacing-correction = #1.5
1857 \override Staff.StaffSpacing #'stem-spacing-correction = #1.5
1861 \paper { raggedright = ##t } }
1864 @cindex SpacingSpanner, overriding properties
1866 Properties of the @internalsref{SpacingSpanner} must be overridden
1867 from the @code{\paper} block, since the @internalsref{SpacingSpanner} is
1868 created before any property commands are interpreted.
1870 \paper @{ \context @{
1872 \override SpacingSpanner #'spacing-increment = #3.0
1879 Internals: @internalsref{SpacingSpanner}, @internalsref{NoteSpacing},
1880 @internalsref{StaffSpacing}, @internalsref{SeparationItem}, and
1881 @internalsref{SeparatingGroupSpanner}.
1885 Spacing is determined on a score wide basis. If you have a score that
1886 changes its character (measured in durations) halfway during the
1887 score, the part containing the longer durations will be spaced too
1890 There is no convenient mechanism to manually override spacing. The
1891 following work-around may be used to insert extra space into a score.
1893 \once \override Score.SeparationItem #'padding = #1
1896 No work-around exists for decreasing the amount of space.
1905 @subsection Line breaking
1908 @cindex breaking lines
1910 Line breaks are normally computed automatically. They are chosen such
1911 that lines look neither cramped nor loose, and that consecutive lines
1912 have similar density.
1914 Occasionally you might want to override the automatic breaks; you can
1915 do this by specifying @code{\break}. This will force a line break at
1916 this point. Line breaks can only occur at places where there are bar
1917 lines. If you want to have a line break where there is no bar line,
1918 you can force an invisible bar line by entering @code{\bar
1919 ""}. Similarly, @code{\noBreak} forbids a line break at a
1923 @cindex regular line breaks
1924 @cindex four bar music.
1926 For line breaks at regular intervals use @code{\break} separated by
1927 skips and repeated with @code{\repeat}:
1929 << \repeat unfold 7 @{
1930 s1 \noBreak s1 \noBreak
1931 s1 \noBreak s1 \break @}
1932 @emph{the real music}
1937 This makes the following 28 measures (assuming 4/4 time) be broken every
1938 4 measures, and only there.
1942 @code{\break}, and @code{\noBreak}.
1943 @cindex @code{\break}
1944 @cindex @code{\noBreak}
1948 Internals: @internalsref{BreakEvent}.
1950 @node Line length and line breaking
1951 @subsection Line length and line breaking
1954 @cindex breaking pages
1956 @cindex @code{indent}
1957 @cindex @code{linewidth}
1959 The most basic settings influencing the spacing are @code{indent} and
1960 @code{linewidth}. They are set in the @code{\paper} block. They
1961 control the indentation of the first line of music, and the lengths of
1964 If @code{raggedright} is set to true in the @code{\paper}
1965 block, then the lines are justified at their natural length. This
1966 useful for short fragments, and for checking how tight the natural
1970 @cindex vertical spacing
1972 The option @code{raggedlast} is similar to @code{raggedright}, but
1973 only affects the last line of the piece. No restrictions are put on
1974 that line. The result is similar to formatting paragraphs. In a
1975 paragraph, the last line simply takes its natural length.
1981 Titles are created for each @code{\score} block, and over a
1984 The contents of the titles are taken from the @code{\header} blocks.
1985 The header block for a book supports the following
1988 The title of the music. Centered on top of the first page.
1990 Subtitle, centered below the title.
1992 Name of the poet, left flushed below the subtitle.
1994 Name of the composer, right flushed below the subtitle.
1996 Meter string, left flushed below the poet.
1998 Name of the opus, right flushed below the composer.
2000 Name of the arranger, right flushed below the opus.
2002 Name of the instrument, centered below the arranger.
2004 To whom the piece is dedicated.
2006 Name of the piece, left flushed below the instrument.
2009 This is a demonstration of the fields available,
2015 subtitle = "(and (the) subtitle)"
2016 subsubtitle = "Sub sub title"
2018 composer = "Composer"
2019 texttranslator = "Text Translator"
2021 arranger = "Arranger"
2022 instrument = "Instrument"
2035 Different fonts may be selected for each element, by using a
2036 @code{\markup}, e.g.
2040 title = \markup { \italic { The italic title } }
2044 A more advanced option is to change the Scheme functions
2045 @code{make-book-title} and @code{make-score-title} functions, defined
2046 in the @code{\bookpaper} of the @code{\book} block. These functions
2047 create a block of titling, given the information in the
2048 @code{\header}. The init file @file{ly/titling.scm} shows how the
2049 default format is created, and it may be used as a template for
2063 @subsection Page breaking
2065 The default page breaking may be overriden by inserting
2066 @code{\pageBreak} or @code{\noPageBreak} commands. These commands are
2067 analogous to @code{\break} and @code{\noBreak}. They should be
2068 inserted with a bar line. These commands force and forbid a page-break
2071 Page breaks are computed by the @code{page-breaking} function in the
2072 @code{\bookpaper} block.
2076 @cindex @code{\pageBreak}
2078 @cindex @code{\noPageBreak}
2082 @subsection Paper size
2086 @cindex @code{papersize}
2088 To change the paper size, there are two commands,
2090 #(set-default-paper-size "a4")
2092 #(set-paper-size "a4")
2095 The second one sets the size of the @code{\paper} block that it is in.
2099 @subsection Page layout
2103 @cindex header, page
2104 @cindex footer, page
2106 LilyPond will do page layout, setting margins and adding headers and
2107 footers to each page.
2109 The default layout responds to the following settings in the
2110 @code{\bookpaper} block
2114 The width of the page
2116 The height of the page
2118 Margin between header and top of the page
2120 Margin between footer and bottom of the page
2122 Distance between top-most music system and the page header
2124 Distance between bottom-most music system and the page footer
2127 The default page header puts the page number and the @code{instrument}
2128 field from the @code{\header} block on a line.
2133 The default footer is empty, except for the first page, where it the
2134 @code{copyright} field from @code{\header} is inserted, and the last
2135 page, where @code{tagline} from @code{\header} is added (the default
2136 tagline is ``Engraved by LilyPond (@var{version})''.
2138 The header and footer are created by the functions @code{make-footer}
2139 and @code{make-header}, defined in @code{\bookpaper}. The default
2140 implementations are in @file{scm/page-layout.scm}.
2142 The page layout itself is done by two functions:
2143 @code{page-music-height} and @code{page-make-stencil}. The former
2144 tells the line-breaking algorithm how much space can be spent on a
2145 page, the latter creates the actual page given the system to put on it.