2 @node Changing defaults
3 @chapter Changing defaults
10 * Fine tuning layout::
14 * Interpretation context::
20 @node Scheme integration
21 @section Scheme integration
25 @cindex Scheme, in-line code
26 @cindex accessing Scheme
27 @cindex evaluating Scheme
30 LilyPond internally uses GUILE, a Scheme-interpreter, to represent
31 data throughout the whole program, and glue together different program
32 modules. For advanced usage, it is sometimes necessary to access and
33 program the Scheme interpreter.
35 Scheme is a full-blown programming language, from the LISP
36 family. and a full discussion is outside the scope of this document.
37 Interested readers are referred to the website
38 @uref{http://www.schemers.org/} for more information on Scheme.
40 The GUILE library for extension is documented at
41 @uref{http://www.gnu.org/software/guile}.
43 When it is installed, the following link should take you to its manual
44 @ref{(guile.info)guile}
52 @subsection Inline Scheme
54 Scheme expressions can be entered in the input file by entering a
55 hash-sign (@code{#}). The expression following the hash-sign is
56 evaluated as Scheme. For example, the boolean value @var{true} is
57 @code{#t} in Scheme, so for LilyPond @var{true} looks like @code{##t},
58 and can be used in property assignments:
60 \set Staff.autoBeaming = ##f
64 @node Setting variables
65 @section Setting variables
67 When the music is converted from notes to print it is interpreted
68 in left-to-right order. This is similar to what happens when we read
69 music. During this step context-sensitive information such as the
70 accidentals to print, and where bar lines must be placed, are stored in
71 variables. These variables are called @emph{context properties}.
72 The properties can also be manipulated from input files. Consider this input:
74 \set Staff.autoBeaming = ##f
78 It sets the property named @code{autoBeaming} in the current staff at
79 this point in the music to @code{##f}, which means `false'. This
80 property controls whether beams are printed automatically:
82 @lilypond[relative=1,fragment,verbatim]
84 \set Staff.autoBeaming = ##f
89 LilyPond includes a built-in programming language, namely, a dialect
90 of Scheme. The argument to @code{\set}, @code{##f}, is an
91 expression in that language. The first hash-mark signals that a piece
92 of Scheme code follows. The second hash character is part of the
93 boolean value true (@code{#t}). Values of other types may be
96 @item a string, enclosed in double quotes, for example,
98 \set Staff.instrument = #"French Horn"
100 @item a boolean: either @code{#t} or @code{#f}, for true and false
103 \set autoBeaming = ##f
104 \set Score.skipBars = ##t
107 @item a number, such as
109 \set Score.currentBarNumber = #20
112 @item a symbol, which is introduced by a quote character, as in
114 \set Staff.crescendoSpanner = #'dashed-line
117 @item a pair, which is also introduced by a quote character, like in
118 the following statements, which set properties to the pairs (-7.5, 6)
119 and (3, 4) respectively:
122 \set Staff.minimumVerticalExtent = #'(-7.5 . 6)
123 \set Staff.timeSignatureFraction = #'(3 . 4)
126 @item a list, which is also introduced by a quote character. In the
127 following example, the @code{breakAlignOrder} property is set to a
130 \set Score.breakAlignOrder =
131 #'(left-edge time-signature key-signatures)
137 There are many different properties. Not all of them are listed in
138 this manual. However, the program reference lists them all in the
139 section @internalsref{Context-properties}, and most properties are
140 demonstrated in one of the
142 @uref{../../../input/test/out-www/collated-files.html,tips-and-tricks}
150 @node Fine tuning layout
151 @section Fine tuning layout
153 Sometimes it is necessary to change music layout by hand. When music
154 is formatted, layout objects are created for each symbol. For
155 example, every clef and every note head is represented by a layout
156 object. These layout objects also carry variables, which we call
157 @emph{layout properties}. By changing these variables from their
158 values, we can alter the look of a formatted score:
160 @lilypond[verbatim,relative]
162 \override Stem #'thickness = #3.0
167 In the example shown here, the layout property @code{thickness} (a
168 symbol) is set to 3 in the @code{Stem} layout objects of the current
169 As a result, the notes following @code{\override} have thicker
172 For the most part, a manual override is needed only on a case by
173 case basis and not for all subsequent instances of the altered
174 property. To accomplish this, simply prefix @code{\once} to the
175 @code{\override} statement and the override will apply only once,
176 immediately reverting to its default setting, i.e.
179 \once \override Stem #'thickness = #3.0
184 \once \override Stem #'thickness = #3.0
189 Some overrides are so common that predefined commands are provided as
190 a short cut. For example, @code{\slurUp} and @code{\stemDown}. These
191 commands are described in
195 @ref{Notation manual}, under the sections for slurs and stems
198 The exact tuning possibilities for each type of layout object are
199 documented in the program reference of the respective
200 object. However, many layout objects share properties, which can be
201 used to apply generic tweaks. We mention a couple of these:
204 @item The @code{extra-offset} property, which
205 @cindex @code{extra-offset}
206 has a pair of numbers as value, moves around objects in the printout.
207 The first number controls left-right movement; a positive number will
208 move the object to the right. The second number controls up-down
209 movement; a positive number will move it higher. The units of these
210 offsets are staff-spaces. The @code{extra-offset} property is a
211 low-level feature: the formatting engine is completely oblivious to
214 In the following example, the second fingering is moved a little to
215 the left, and 1.8 staff space downwards:
217 @cindex setting object properties
219 @lilypond[relative=1,verbatim]
222 \once \override Fingering
223 #'extra-offset = #'(-0.3 . -1.8)
228 Setting the @code{transparent} property will cause an object to be printed
229 in `invisible ink': the object is not printed, but all its other
230 behavior is retained. The object still takes up space, it takes part in
231 collisions, and slurs, and ties and beams can be attached to it.
233 @cindex transparent objects
234 @cindex removing objects
235 @cindex invisible objects
236 The following example demonstrates how to connect different voices
237 using ties. Normally, ties only connect two notes in the same
238 voice. By introducing a tie in a different voice, and blanking a stem
239 in that voice, the tie appears to cross voices:
241 @lilypond[fragment,relative=1,verbatim]
243 \once \override Stem #'transparent = ##t
251 The @code{padding} property for objects with
252 @cindex @code{padding}
253 @code{side-position-interface} can be set to increase distance between
254 symbols that are printed above or below notes. We only give an
255 example; a more elaborate explanation is in @ref{Constructing a
258 @lilypond[relative=1,verbatim]
260 \override Script #'padding = #3
266 More specific overrides are also possible. The notation manual
267 discusses in depth how to figure out these statements for yourself, in
274 @section Tuning output
276 There are situations where default layout decisions are not
277 sufficient. In this section we discuss ways to override these
280 Formatting is internally done by manipulating so called objects
281 (graphic objects). Each object carries with it a set of properties
282 (object or layout properties) specific to that object. For example, a
283 stem object has properties that specify its direction, length and
286 The most direct way of tuning the output is by altering the values of
287 these properties. There are two ways of doing that: first, you can
288 temporarily change the definition of one type of object, thus
289 affecting a whole set of objects. Second, you can select one specific
290 object, and set a layout property in that object.
292 Do not confuse layout properties with translation
293 properties. Translation properties always use a mixed caps style
294 naming, and are manipulated using @code{\set} and @code{\unset}:
296 \set Context.propertyName = @var{value}
299 Layout properties are use Scheme style variable naming, i.e. lower
300 case words separated with dashes. They are symbols, and should always
301 be quoted using @code{#'}. For example, this could be an imaginary
302 layout property name:
304 #'layout-property-name
310 * Constructing a tweak::
317 @subsection Tuning objects
319 @cindex object description
321 The definition of an object is a list of default object
322 properties. For example, the definition of the Stem object (available
323 in @file{scm/define-grobs.scm}), includes the following definitions
324 for @internalsref{Stem}:
328 (beamed-lengths . (3.5 3.5 3.5 4.5 5.0))
329 (Y-extent-callback . ,Stem::height)
334 Adding variables on top of this existing definition overrides the
335 system default, and alters the resulting appearance of the layout
341 Changing a variable for only one object is commonly achieved with
345 \once \override @var{context}.@var{objectname}
346 @var{symbol} = @var{value}
348 Here @var{symbol} is a Scheme expression of symbol type, @var{context}
349 and @var{objectname} is a string and @var{value} is a Scheme expression.
350 This command applies a setting only during one moment in the score.
352 In the following example, only one @internalsref{Stem} object is
353 changed from its original setting:
355 @lilypond[verbatim,fragment,relative=1]
357 \once \override Voice.Stem #'thickness = #4
363 For changing more objects, the same command, without @code{\once} can
366 \override @var{context}.@var{objectname} @var{symbol} = @var{value}
368 This command adds @code{@var{symbol} = @var{value}} to the definition
369 of @var{objectname} in the context @var{context}, and this definition
370 stays in place until it is removed.
372 An existing definition may be removed by the following command:
375 \property @var{context}.@var{objectname} \revert @var{symbol}
381 c'4 \override Stem #'thickness = #4.0
383 c'4 \revert Stem #'thickness
387 The following example gives exactly the same result as the previous
388 one (assuming the system default for stem thickness is 1.3):
391 c'4 \override Stem #'thickness = #4.0
393 c'4 \override Stem #'thickness = #1.3
397 Reverting a setting which was not set in the first place has no
403 Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
404 @internalsref{PropertySet}, @internalsref{All-backend-properties}, and
405 @internalsref{All-layout-objects}.
410 The back-end is not very strict in type-checking object properties.
411 Cyclic references in Scheme values for properties can cause hangs
415 * Constructing a tweak::
421 @node Constructing a tweak
422 @subsection Constructing a tweak
425 @cindex internal documentation
426 @cindex finding graphical objects
427 @cindex graphical object descriptions
429 @cindex @code{\override}
431 @cindex internal documentation
435 Three pieces of information are required to use @code{\override} and
436 @code{\set}: the name of the layout object, the context and the name
437 of the property. We demonstrate how to glean this information from
438 the notation manual and the generated documentation.
440 The generated documentation is a set of HTML pages which should be
441 included if you installed a binary distribution, typically in
442 @file{/usr/share/doc/lilypond}. They are also available on the web:
443 go to the @uref{http://lilypond.org,LilyPond website}, click
444 ``Documentation'', select the correct version, and click then
445 ``Program reference.'' It is advisable to bookmark the local HTML
446 files. They will load faster than the ones on the web. If you use the
447 version from the web, you must check whether the documentation matches
448 the program version: it is generated from the definitions that the
449 program uses, and therefore it is strongly tied to the LilyPond
453 @c [TODO: revise for new site.]
455 Suppose we want to move the fingering indication in the fragment below:
457 @lilypond[relative=2,verbatim]
463 If you visit the documentation of @code{Fingering} (in @ref{Fingering
464 instructions}), you will notice that there is written:
469 Internals: @internalsref{FingerEvent} and @internalsref{Fingering}.
476 In other words, the fingerings once entered, are internally stored as
477 @code{FingerEvent} music objects. When printed, a @code{Fingering}
478 layout object is created for every @code{FingerEvent}.
480 The Fingering object has a number of different functions, and each of
481 those is captured in an interface. The interfaces are listed under
482 @internalsref{Fingering} in the program reference.
486 The @code{Fingering} object has a fixed size
487 (@internalsref{item-interface}), the symbol is a piece of text
488 (@internalsref{text-interface}), whose font can be set
489 (@internalsref{font-interface}). It is centered horizontally
490 (@internalsref{self-alignment-interface}), it is placed next to other
491 objects (@internalsref{side-position-interface}) vertically, and its
492 placement is coordinated with other scripts
493 (@internalsref{text-script-interface}). It also has the standard
494 @internalsref{grob-interface} (grob stands for Graphical object)
496 @cindex graphical object
497 @cindex layout object
498 @cindex object, layout
499 with all the variables that come with
500 it. Finally, it denotes a fingering instruction, so it has
501 @internalsref{finger-interface}.
503 For the vertical placement, we have to look under
504 @code{side-position-interface}:
506 @code{side-position-interface}
508 Position a victim object (this one) next to other objects (the
509 support). In this case, the property @code{direction} signifies where to put the
510 victim object relative to the support (left or right, up or down?)
515 below this description, the variable @code{padding} is described as
519 (dimension, in staff space)
521 add this much extra space between objects that are next to each
522 other. Default value: @code{0.6}
526 By increasing the value of @code{padding}, we can move away the
527 fingering. The following command inserts 3 staff spaces of white
528 between the note and the fingering:
530 \once \override Fingering #'padding = #3
533 Inserting this command before the Fingering object is created,
534 i.e. before @code{c2}, yields the following result:
536 @lilypond[relative=2,fragment,verbatim]
537 \once \override Fingering
544 The context name @code{Voice} in the example above can be determined
545 as follows. In the documentation for @internalsref{Fingering}, it says
547 Fingering grobs are created by: @internalsref{Fingering_engraver} @c
550 Clicking @code{Fingering_engraver} shows the documentation of
551 the module responsible for interpreting the fingering instructions and
552 translating them to a @code{Fingering} object. Such a module is called
553 an @emph{engraver}. The documentation of the @code{Fingering_engraver}
556 Fingering_engraver is part of contexts: Voice
558 so tuning the settings for Fingering should be done with
560 \override Fingering @dots{}
563 Of course, the tweak may also done in a larger context than
564 @code{Voice}, for example, @internalsref{Staff} or
565 @internalsref{Score}.
569 Internals: the program reference also contains alphabetical lists of
570 @internalsref{Contexts}, @internalsref{All-layout-objects} and
571 @internalsref{Music-expressions}, so you can also find which objects
572 to tweak by browsing the internals document.
578 @subsection Font selection
580 The most common thing to change about the appearance of fonts is their
581 size. The font size of any context can be easily changed by setting
582 the @code{fontSize} property for that context. Its value is a number:
583 negative numbers make the font smaller, positive numbers larger. An
584 example is given below:
586 @lilypond[fragment,relative=1,verbatim]
587 c4 c4 \set fontSize = #-1
590 This command will set @code{font-size} (see below), and does
591 not change the size of variable symbols, such as beams or slurs.
593 One of the uses of @code{fontSize} is to get smaller symbols for cue
594 notes. An elaborate example of those is in
595 @inputfileref{input/test,cue-notes.ly}.
597 @cindex magnification
600 The font used for printing a object can be selected by setting
601 @code{font-name}, e.g.
603 \override Staff.TimeSignature
604 #'font-name = #"cmr17"
608 Any font can be used, as long as it is available to @TeX{}. Possible
609 fonts include foreign fonts or fonts that do not belong to the
610 Computer Modern font family. The size of fonts selected in this way
611 can be changed with the @code{font-magnification} property. For
612 example, @code{2.0} blows up all letters by a factor 2 in both
616 @cindex font magnification
618 Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
619 can also be adjusted with a more fine-grained mechanism. By setting
620 the object properties described below, you can select a different font;
621 all three mechanisms work for every object that supports
622 @code{font-interface}:
627 is a symbol indicating the general class of the typeface. Supported are
628 @code{roman} (Computer Modern), @code{braces} (for piano staff
629 braces), @code{music} (the standard music font, including ancient
630 glyphs), @code{dynamic} (for dynamic signs) and @code{typewriter}.
633 is a symbol indicating the shape of the font, there are typically several
634 font shapes available for each font family. Choices are @code{italic},
635 @code{caps} and @code{upright}.
638 is a symbol indicating the series of the font. There are typically several
639 font series for each font family and shape. Choices are @code{medium}
644 For any of these properties, the value @code{*} (i.e. the symbol
645 @code{*}, entered as @code{#'*}), acts as a wildcard. This can be used
646 to override default setting, which are always present. For example:
648 \override Lyrics .LyricText #'font-series = #'bold
649 \override Lyrics .LyricText #'font-family = #'typewriter
650 \override Lyrics .LyricText #'font-shape = #'*
653 @cindex @code{font-style}
655 The font size is set by modifying the @code{font-size} property. Its
656 value is a number indicating the size relative to the standard size.
657 Each step up is an increase of approximately 12% of the font size. Six
658 steps is exactly a factor two. The Scheme function @code{magstep}
659 converts a @code{font-size} number to a scaling factor.
661 LilyPond has fonts in different design sizes: the music fonts for
662 smaller sizes are chubbier, while the text fonts are relatively wider.
663 Font size changes are achieved by scaling the design size that is
664 closest to the desired size.
666 The @code{font-size} mechanism does not work for fonts selected
667 through @code{font-name}. These may be scaled with
668 @code{font-magnification}.
672 The following commands set @code{fontSize} for the current voice.
676 @cindex @code{\small}
678 @cindex @code{\normalsize}
683 Init files: @file{ly/declarations-init.ly} contains hints how new
684 fonts may be added to LilyPond.
688 There is no style sheet provided for other fonts besides the @TeX{}
689 Computer Modern family.
691 @cindex font selection
692 @cindex font magnification
693 @cindex @code{font-interface}
704 LilyPond has an internal mechanism to typeset texts. You can access it
705 with the keyword @code{\markup}. Within markup mode, you can enter texts
706 similar to lyrics: simply enter them, surrounded by spaces:
709 @lilypond[verbatim,fragment,relative=1]
711 c1_\markup { hi there }
712 c1^\markup { hi \bold there, is \italic anyone home? }
715 @cindex font switching
717 The markup in the example demonstrates font switching commands. The
718 command @code{\bold} and @code{\italic} only apply to the first
719 following word; enclose a set of texts with braces to apply a command
722 \markup @{ \bold @{ hi there @} @}
726 For clarity, you can also do this for single arguments, e.g.
729 \markup { is \italic { anyone } home }
732 @cindex font size, texts
735 In markup mode you can compose expressions, similar to mathematical
736 expressions, XML documents and music expressions. The braces group
737 notes into horizontal lines. Other types of lists also exist: you can
738 stack expressions grouped with @code{<}, and @code{>} vertically with
739 the command @code{\column}. Similarly, @code{\center-align} aligns
740 texts by their center lines:
742 @lilypond[verbatim,fragment,relative=1]
743 c1^\markup { \column < a bbbb c > }
744 c1^\markup { \center-align < a bbbb c > }
745 c1^\markup { \line < a b c > }
749 Markups can be stored in variables, and these variables
750 may be attached to notes, like
752 allegro = \markup { \bold \large { Allegro } }
753 \notes { a^\allegro b c d }
757 Some objects have alignment procedures of their own, which cancel out
758 any effects of alignments applied to their markup arguments as a
759 whole. For example, the @internalsref{RehearsalMark} is horizontally
760 centered, so using @code{\mark \markup @{ \left-align .. @}} has no
761 effect. Similarly, whole texts over notes cannot be moved vertically
762 with @code{\raise}. For moving and aligning complete objects, grob
763 properties should be used.
769 Init files: @file{scm/new-markup.scm}.
774 Text layout is ultimately done by @TeX{}, which does kerning of
775 letters. LilyPond does not account for kerning, so texts will be
776 spaced slightly too wide.
778 Syntax errors for markup mode are confusing.
780 Markup texts cannot be used in the titling of the @code{\header}
781 field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
787 * Overview of text markup commands::
790 @node Overview of text markup commands
791 @subsection Overview of text markup commands
793 @include markup-commands.tely
797 @section Global layout
799 The global layout determined by three factors: the page layout, the
800 line breaks and the spacing. These all influence each other. The
801 choice of spacing determines how densely each system of music is set,
802 which influences where line breaks breaks are chosen, and thus
803 ultimately how many pages a piece of music takes. This section
804 explains how to tune the algorithm for spacing.
806 Globally spoken, this procedure happens in three steps: first,
807 flexible distances (``springs'') are chosen, based on durations. All
808 possible line breaking combination are tried, and the one with the
809 best results---a layout that has uniform density and requires as
810 little stretching or cramping as possible---is chosen. When the score
811 is processed by @TeX{}, each page is filled with systems, and page breaks
812 are chosen whenever the page gets full.
818 * Horizontal spacing::
825 @node Vertical spacing
826 @subsection Vertical spacing
828 @cindex vertical spacing
829 @cindex distance between staves
830 @cindex staff distance
831 @cindex between staves, distance
832 @cindex staffs per page
833 @cindex space between staves
835 The height of each system is determined automatically by LilyPond, to
836 keep systems from bumping into each other, some minimum distances are
837 set. By changing these, you can put staves closer together, and thus
838 put more systems onto one page.
840 Normally staves are stacked vertically. To make
841 staves maintain a distance, their vertical size is padded. This is
842 done with the property @code{minimumVerticalExtent}. It takes a pair
843 of numbers, so if you want to make it smaller from its, then you could
846 \set Staff.minimumVerticalExtent = #'(-4 . 4)
848 This sets the vertical size of the current staff to 4 staff spaces on
849 either side of the center staff line. The argument of
850 @code{minimumVerticalExtent} is interpreted as an interval, where the
851 center line is the 0, so the first number is generally negative. The
852 staff can be made larger at the bottom by setting it to @code{(-6
855 The piano staves are handled a little differently: to make cross-staff
856 beaming work correctly, it is necessary that the distance between staves
857 is fixed beforehand. This is also done with a
858 @internalsref{VerticalAlignment} object, created in
859 @internalsref{PianoStaff}. In this object the distance between the
860 staves is fixed by setting @code{forced-distance}. If you want to
861 override this, use a @code{\translator} block as follows:
866 \override VerticalAlignment #'forced-distance = #9
871 This would bring the staves together at a distance of 9 staff spaces,
872 measured from the center line of each staff.
876 Internals: Vertical alignment of staves is handled by the
877 @internalsref{VerticalAlignment} object.
882 @node Horizontal spacing
883 @subsection Horizontal Spacing
885 The spacing engine translates differences in durations into
886 stretchable distances (``springs'') of differing lengths. Longer
887 durations get more space, shorter durations get less. The shortest
888 durations get a fixed amount of space (which is controlled by
889 @code{shortest-duration-space} in the @internalsref{SpacingSpanner} object).
890 The longer the duration, the more space it gets: doubling a
891 duration adds a fixed amount (this amount is controlled by
892 @code{spacing-increment}) of space to the note.
894 For example, the following piece contains lots of half, quarter and
895 8th notes, the eighth note is followed by 1 note head width (NHW).
896 The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
897 @lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8
901 Normally, @code{shortest-duration-space} is set to 1.2, which is the
902 width of a note head, and @code{shortest-duration-space} is set to
903 2.0, meaning that the shortest note gets 2 NHW (i.e. 2 times
904 @code{shortest-duration-space}) of space. For normal notes, this space
905 is always counted from the left edge of the symbol, so the shortest
906 notes are generally followed by one NHW of space.
908 If one would follow the above procedure exactly, then adding a single
909 32th note to a score that uses 8th and 16th notes, would widen up the
910 entire score a lot. The shortest note is no longer a 16th, but a 32nd,
911 thus adding 1 NHW to every note. To prevent this, the
912 shortest duration for spacing is not the shortest note in the score,
913 but the most commonly found shortest note. Notes that are even
914 shorter this are followed by a space that is proportional to their
915 duration relative to the common shortest note. So if we were to add
916 only a few 16th notes to the example above, they would be followed by
919 @lilypond[fragment,verbatim,relative=2]
920 c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4
923 The most common shortest duration is determined as follows: in every
924 measure, the shortest duration is determined. The most common short
925 duration, is taken as the basis for the spacing, with the stipulation
926 that this shortest duration should always be equal to or shorter than
927 1/8th note. The shortest duration is printed when you run lilypond
928 with @code{--verbose}. These durations may also be customized. If you
929 set the @code{common-shortest-duration} in
930 @internalsref{SpacingSpanner}, then this sets the base duration for
931 spacing. The maximum duration for this base (normally 1/8th), is set
932 through @code{base-shortest-duration}.
934 @cindex @code{common-shortest-duration}
935 @cindex @code{base-shortest-duration}
936 @cindex @code{stem-spacing-correction}
937 @cindex @code{spacing}
939 In the introduction it was explained that stem directions influence
940 spacing. This is controlled with @code{stem-spacing-correction}
941 property in @internalsref{NoteSpacing}, which are generated for every
942 @internalsref{Voice} context. The @code{StaffSpacing} object
943 (generated at @internalsref{Staff} context) contains the same property
944 for controlling the stem/bar line spacing. The following example
945 shows these corrections, once with default settings, and once with
946 exaggerated corrections:
952 \override Staff.NoteSpacing #'stem-spacing-correction
954 \override Staff.StaffSpacing #'stem-spacing-correction
959 \paper { raggedright = ##t } }
962 @cindex SpacingSpanner, overriding properties
964 Properties of the @internalsref{SpacingSpanner} must be overridden
965 from the @code{\paper} block, since the @internalsref{SpacingSpanner} is
966 created before any property commands are interpreted.
968 \paper @{ \translator @{
970 SpacingSpanner \override #'spacing-increment = #3.0
977 Internals: @internalsref{SpacingSpanner}, @internalsref{NoteSpacing},
978 @internalsref{StaffSpacing}, @internalsref{SeparationItem}, and
979 @internalsref{SeparatingGroupSpanner}.
983 Spacing is determined on a score wide basis. If you have a score that
984 changes its character (measured in durations) halfway during the
985 score, the part containing the longer durations will be spaced too
988 There is no convenient mechanism to manually override spacing.
993 @subsection Font size
994 @cindex font size, setting
995 @cindex staff size, setting
996 @cindex @code{paper} file
998 The Feta font provides musical symbols at eight seven different
999 sizes. Each font is tuned for a different staff size: at smaller sizes
1000 the font gets heavier, to match the relatively heavier staff lines.
1001 The recommended font sizes are listed in the following table:
1003 @multitable @columnfractions .25 .25 .25 .25
1006 @tab @b{staff height (pt)}
1007 @tab @b{staff height (mm)}
1049 @c modern rental material ?
1053 These fonts are available in any sizes. The context property
1054 @code{fontSize} and the layout property @code{staff-space} (in
1055 @internalsref{StaffSymbol}) can be used to tune size for individual
1056 staffs. The size of individual staffs are relative to the global size,
1057 which can be set in the following manner:
1060 #(set-global-staff-size 14)
1063 This sets the global default size to 14pt staff height, and scales all
1069 @subsection Line breaking
1072 @cindex breaking lines
1074 Line breaks are normally computed automatically. They are chosen such
1075 that lines look neither cramped nor loose, and that consecutive lines
1076 have similar density.
1078 Occasionally you might want to override the automatic breaks; you can
1079 do this by specifying @code{\break}. This will force a line break at
1080 this point. Line breaks can only occur at places where there are bar
1081 lines. If you want to have a line break where there is no bar line,
1082 you can force an invisible bar line by entering @code{\bar
1083 ""}. Similarly, @code{\noBreak} forbids a line break at a
1087 @cindex regular line breaks
1088 @cindex four bar music.
1090 For line breaks at regular intervals use @code{\break} separated by
1091 skips and repeated with @code{\repeat}:
1093 << \repeat unfold 7 @{
1094 s1 \noBreak s1 \noBreak
1095 s1 \noBreak s1 \break @}
1096 @emph{the real music}
1101 This makes the following 28 measures (assuming 4/4 time) be broken every
1102 4 measures, and only there.
1106 @code{\break}, @code{\noBreak}
1107 @cindex @code{\break}
1108 @cindex @code{\noBreak}
1112 Internals: @internalsref{BreakEvent}.
1116 @subsection Page layout
1119 @cindex breaking pages
1121 @cindex @code{indent}
1122 @cindex @code{linewidth}
1124 The most basic settings influencing the spacing are @code{indent} and
1125 @code{linewidth}. They are set in the @code{\paper} block. They
1126 control the indentation of the first line of music, and the lengths of
1129 If @code{raggedright} is set to true in the @code{\paper}
1130 block, then the lines are justified at their natural length. This
1131 useful for short fragments, and for checking how tight the natural
1135 @cindex vertical spacing
1137 The page layout process happens outside the LilyPond formatting
1138 engine: variables controlling page layout are passed to the output,
1139 and are further interpreted by @code{lilypond} wrapper program. It
1140 responds to the following variables in the @code{\paper} block. The
1141 variable @code{textheight} sets the total height of the music on each
1142 page. The spacing between systems is controlled with
1143 @code{interscoreline}, its default is 16pt. The distance between the
1144 score lines will stretch in order to fill the full page
1145 @code{interscorelinefill} is set to a positive number. In that case
1146 @code{interscoreline} specifies the minimum spacing.
1148 @cindex @code{textheight}
1149 @cindex @code{interscoreline}
1150 @cindex @code{interscorelinefill}
1152 If the variable @code{lastpagefill} is defined,
1153 @c fixme: this should only be done if lastpagefill= #t
1154 systems are evenly distributed vertically on the last page. This
1155 might produce ugly results in case there are not enough systems on the
1156 last page. The @command{lilypond-book} command ignores
1157 @code{lastpagefill}. See @ref{lilypond-book manual} for more
1160 @cindex @code{lastpagefill}
1162 Page breaks are normally computed by @TeX{}, so they are not under
1163 direct control of LilyPond. However, you can insert a commands into
1164 the @file{.tex} output to instruct @TeX{} where to break pages. This
1165 is done by setting the @code{between-systems-strings} on the
1166 @internalsref{NonMusicalPaperColumn} where the system is broken.
1167 An example is shown in @inputfileref{input/regression,between-systems.ly}.
1168 The predefined command @code{\newpage} also does this.
1172 @cindex @code{papersize}
1174 To change the paper size, use the following Scheme code:
1177 #(set-paper-size "a4")
1184 @cindex @code{\newpage}
1190 In this manual: @ref{Invoking lilypond}.
1192 Examples: @inputfileref{input/regression,between-systems.ly}.
1194 Internals: @internalsref{NonMusicalPaperColumn}.
1198 LilyPond has no concept of page layout, which makes it difficult to
1199 reliably choose page breaks in longer pieces.
1202 @node Interpretation context
1203 @section Interpretation context
1206 * Creating contexts::
1207 * Default contexts::
1208 * Context properties::
1209 * Defining contexts::
1210 * Changing contexts locally::
1211 * Engravers and performers::
1212 * Defining new contexts::
1216 Interpretation contexts are objects that only exist during program
1217 run. During the interpretation phase (when @code{interpreting music}
1218 is printed on the standard output), the music expression in a
1219 @code{\score} block is interpreted in time order, the same order in
1220 which we hear and play the music. During this phase, the interpretation
1221 context holds the state for the current point within the music, for
1224 @item What notes are playing at this point?
1226 @item What symbols will be printed at this point?
1228 @item What is the current key signature, time signature, point within
1232 Contexts are grouped hierarchically: A @internalsref{Voice} context is
1233 contained in a @internalsref{Staff} context (because a staff can contain
1234 multiple voices at any point), a @internalsref{Staff} context is contained in
1235 @internalsref{Score}, @internalsref{StaffGroup}, or
1236 @internalsref{ChoirStaff} context.
1238 Contexts associated with sheet music output are called @emph{notation
1239 contexts}, those for sound output are called @emph{performance
1240 contexts}. The default definitions of the standard notation and
1241 performance contexts can be found in @file{ly/engraver-init.ly} and
1242 @file{ly/performer-init.ly}, respectively.
1245 @node Creating contexts
1246 @subsection Creating contexts
1247 @cindex @code{\context}
1248 @cindex context selection
1250 Contexts for a music expression can be selected manually, using one of
1251 the following music expressions:
1254 \new @var{contexttype} @var{musicexpr}
1255 \context @var{contexttype} [= @var{contextname}] @var{musicexpr}
1259 This means that @var{musicexpr} should be interpreted within a context
1260 of type @var{contexttype} (with name @var{contextname} if specified).
1261 If no such context exists, it will be created:
1263 @lilypond[verbatim,raggedright]
1265 \notes \relative c'' {
1266 c4 <<d4 \context Staff = "another" e4>> f
1272 In this example, the @code{c} and @code{d} are printed on the default
1273 staff. For the @code{e}, a context @code{Staff} called @code{another}
1274 is specified; since that does not exist, a new context is created.
1275 Within @code{another}, a (default) Voice context is created for the
1276 @code{e4}. A context is ended when when all music referring it has
1277 finished, so after the third quarter, @code{another} is removed.
1279 The @code{\new} construction creates a context with a
1280 generated, unique @var{contextname}. An expression with
1281 @code{\new} always leads to a new context. This is convenient
1282 for creating multiple staffs, multiple lyric lines, etc.
1284 When using automatic staff changes, automatic phrasing, etc., the
1285 context names have special meanings, so @code{\new} cannot be
1289 @node Default contexts
1290 @subsection Default contexts
1292 Every top level music is interpreted by the @code{Score} context; in
1293 other words, you may think of @code{\score} working like
1297 \context Score @var{music}
1301 Music expressions inherit their context from the enclosing music
1302 expression. Hence, it is not necessary to explicitly specify
1303 @code{\context} for most expressions. In
1304 the following example, only the sequential expression has an explicit
1305 context. The notes contained therein inherit the @code{goUp} context
1306 from the enclosing music expression.
1308 @lilypond[verbatim,raggedright]
1309 \notes \context Voice = goUp { c'4 d' e' }
1313 Second, contexts are created automatically to be able to interpret the
1314 music expressions. Consider the following example:
1316 @lilypond[verbatim,raggedright]
1317 \score { \notes { c'4-( d' e'-) } }
1321 The sequential music is interpreted by the Score context initially,
1322 but when a note is encountered, contexts are setup to accept that
1323 note. In this case, a @code{Voice}, and @code{Staff}
1324 context are created. The rest of the sequential music is also
1325 interpreted with the same @code{Voice}, and
1326 @code{Staff} context, putting the notes on the same staff, in the same
1329 @node Context properties
1330 @subsection Context properties
1332 Contexts have properties. These properties are set from the @file{.ly}
1333 file using the following expression:
1334 @cindex context properties
1335 @cindex properties, context
1338 \set @var{contextname}.@var{propname} = @var{value}
1342 Sets the @var{propname} property of the context @var{contextname} to
1343 the specified Scheme expression @var{value}. Both @var{propname} and
1344 @var{contextname} are strings, which can often be written unquoted.
1347 Properties that are set in one context are inherited by all of the
1348 contained contexts. This means that a property valid for the
1349 @internalsref{Voice} context can be set in the @internalsref{Score} context
1350 (for example) and thus take effect in all @internalsref{Voice} contexts.
1352 Properties can be unset using the following statement.
1354 \unset @var{contextname}.@var{propname}
1357 @cindex properties, unsetting
1358 @cindex @code{\unset}
1361 This removes the definition of @var{propname} in @var{contextname}. If
1362 @var{propname} was not defined in @var{contextname} (but was inherited
1363 from a higher context), then this has no effect.
1365 If @var{contextname} is left out, then it defaults to the current
1366 ``bottom'' context: this is a context like @internalsref{Voice} that
1367 cannot contain any other contexts.
1370 @node Defining contexts
1371 @subsection Defining contexts
1373 @cindex context definition
1374 @cindex translator definition
1376 The most common way to create a new context definition is by extending
1377 an existing one. An existing context from the paper block is copied
1378 by referencing a context identifier:
1383 @var{context-identifier}
1389 Every predefined context has a standard identifier. For example, the
1390 @code{Staff} context can be referred to as @code{\StaffContext}.
1392 The context can then be modified by setting or changing properties,
1397 Stem \set #'thickness = #2.0
1398 defaultBarType = #"||"
1401 These assignments happen before interpretation starts, so a property
1402 command will override any predefined settings.
1408 It is not possible to collect multiple property assignments in a
1409 variable, and apply to one @code{\translator} definition by
1410 referencing that variable.
1412 @node Changing contexts locally
1413 @subsection Changing contexts locally
1416 Extending an existing context can also be done locally. A piece of
1417 music can be interpreted in a changed context by using the following syntax
1421 @var{context modifications}
1425 These statements comes between @code{\new} or @code{\context} and the
1426 music to be interpreted. The @var{context modifications} property
1427 settings and @code{\remove}, @code{\consists} and @code{\consistsend}
1428 commands. The syntax is similar to the @code{\translator} block.
1430 The following example shows how a staff is created with bigger spaces,
1431 and without a @code{Clef_engraver}.
1433 @lilypond[relative=1,fragment,verbatim]
1435 \new Staff { c4 es4 g2 }
1437 \override StaffSymbol #'staff-space = #(magstep 1.5)
1439 \remove "Clef_engraver"
1447 The command @code{\with} has no effect on contexts that already
1451 @node Engravers and performers
1452 @subsection Engravers and performers
1455 Each context is composed of a number of building blocks, or plug-ins
1456 called engravers. An engraver is a specialized C++ class that is
1457 compiled into the executable. Typically, an engraver is responsible
1458 for one function: the @code{Slur_engraver} creates only @code{Slur}
1459 objects, and the @code{Skip_event_swallow_translator} only swallows
1460 (silently gobbles) @code{SkipEvent}s.
1467 An existing context definition can be changed by adding or removing an
1468 engraver. The syntax for these operations is
1470 \consists @var{engravername}
1471 \remove @var{engravername}
1474 @cindex @code{\consists}
1475 @cindex @code{\remove}
1478 Here @var{engravername} is a string, the name of an engraver in the
1479 system. In the following example, the @code{Clef_engraver} is removed
1480 from the Staff context. The result is a staff without a clef, where
1481 the middle C is at its default position, the center line:
1483 @lilypond[verbatim,raggedright]
1491 \remove Clef_engraver
1497 A list of all engravers is in the internal documentation,
1498 see @internalsref{Engravers}.
1500 @node Defining new contexts
1501 @subsection Defining new contexts
1504 It is also possible to define new contexts from scratch. To do this,
1505 you must define give the new context a name. In the following
1506 example, a very simple Staff context is created: one that will put
1507 note heads on a staff symbol.
1511 \type "Engraver_group_engraver"
1514 \consists "Staff_symbol_engraver"
1515 \consists "Note_head_engraver"
1516 \consistsend "Axis_group_engraver"
1521 The argument of @code{\type} is the name for a special engraver that
1522 handles cooperation between simple engravers such as
1523 @code{Note_head_engraver} and @code{Staff_symbol_engraver}. This
1524 should always be @code{Engraver_group_engraver} (unless you are
1525 defining a Score context from scratch, in which case
1526 @code{Score_engraver} must be used).
1528 The complete list of context modifiers is the following:
1530 @item @code{\alias} @var{alternate-name}:
1531 This specifies a different name. In the above example,
1532 @code{\set Staff.X = Y} will also work on @code{SimpleStaff}s.
1534 @item @code{\consistsend} @var{engravername}:
1535 Analogous to @code{\consists}, but makes sure that
1536 @var{engravername} is always added to the end of the list of
1539 Engravers that group context objects into axis groups or alignments
1540 need to be at the end of the list. @code{\consistsend} insures that
1541 engravers stay at the end even if a user adds or removes engravers.
1543 @item @code{\accepts} @var{contextname}:
1544 This context can contains @var{contextname} contexts. The first
1545 @code{\accepts} is created as a default context when events (e.g. notes
1546 or rests) are encountered.
1548 @item @code{\denies}:
1549 The opposite of @code{\accepts}.
1551 @item @code{\name} @var{contextname}:
1552 This sets the type name of the context, e.g. @code{Staff},
1553 @code{Voice}. If the name is not specified, the translator will not
1562 @node Output details
1563 @section Output details
1565 The default output format is La@TeX{}, which should be run
1566 through La@TeX{}. Using the option @option{-f}
1567 (or @option{--format}) other output formats can be selected also, but
1568 currently none of them work reliably.
1570 At the beginning of the output file, various global parameters are
1571 defined. Then the file @file{lilyponddefs.tex} is loaded to define
1572 the macros used in the code which follows. @file{lilyponddefs.tex}
1573 includes various other files, partially depending on the global
1576 Now the music is output system by system (a `system' consists of all
1577 staves belonging together). From @TeX{}'s point of view, a system is an
1578 @code{\hbox} which contains a lowered @code{\vbox} so that it is centered
1579 vertically on the baseline of the text. Between systems,
1580 @code{\interscoreline} is inserted vertically to have stretchable space.
1581 The horizontal dimension of the @code{\hbox} is given by the
1582 @code{linewidth} parameter from LilyPond's @code{\paper} block.
1584 After the last system LilyPond emits a stronger variant of
1585 @code{\interscoreline} only if the macro
1586 @code{\lilypondpaperlastpagefill} is not defined (flushing the systems
1587 to the top of the page). You can avoid that by setting the variable
1588 @code{lastpagefill} in LilyPond's @code{\paper} block.
1590 It is possible to fine-tune the vertical offset further by defining the
1591 macro @code{\lilypondscoreshift}:
1594 \def\lilypondscoreshift@{0.25\baselineskip@}
1598 where @code{\baselineskip} is the distance from one text line to the next.
1600 Here an example how to embed a small LilyPond file @code{foo.ly} into
1601 running La@TeX{} text without using the @code{lilypond-book} script
1602 (@pxref{lilypond-book manual}):
1605 \documentclass@{article@}
1607 \def\lilypondpaperlastpagefill@{@}
1609 \def\lilypondscoreshift@{0.25\baselineskip@}
1612 This is running text which includes an example music file
1618 The file @file{foo.tex} has been simply produced with
1624 The call to @code{\lineskip} assures that there is enough vertical space
1625 between the LilyPond box and the surrounding text lines.