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::
311 * Selecting font sizes::
318 @subsection Tuning objects
320 @cindex object description
322 The definition of an object is a list of default object
323 properties. For example, the definition of the Stem object (available
324 in @file{scm/define-grobs.scm}), includes the following definitions
325 for @internalsref{Stem}:
329 (beamed-lengths . (3.5 3.5 3.5 4.5 5.0))
330 (Y-extent-callback . ,Stem::height)
335 Adding variables on top of this existing definition overrides the
336 system default, and alters the resulting appearance of the layout
342 Changing a variable for only one object is commonly achieved with
346 \once \override @var{context}.@var{objectname}
347 @var{symbol} = @var{value}
349 Here @var{symbol} is a Scheme expression of symbol type, @var{context}
350 and @var{objectname} is a string and @var{value} is a Scheme expression.
351 This command applies a setting only during one moment in the score.
353 In the following example, only one @internalsref{Stem} object is
354 changed from its original setting:
356 @lilypond[verbatim,fragment,relative=1]
358 \once \override Voice.Stem #'thickness = #4
364 For changing more objects, the same command, without @code{\once} can
367 \override @var{context}.@var{objectname} @var{symbol} = @var{value}
369 This command adds @code{@var{symbol} = @var{value}} to the definition
370 of @var{objectname} in the context @var{context}, and this definition
371 stays in place until it is removed.
373 An existing definition may be removed by the following command:
376 \property @var{context}.@var{objectname} \revert @var{symbol}
382 c'4 \override Stem #'thickness = #4.0
384 c'4 \revert Stem #'thickness
390 Reverting a setting which was not set in the first place has no
396 Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
397 @internalsref{PropertySet}, @internalsref{All-backend-properties}, and
398 @internalsref{All-layout-objects}.
403 The back-end is not very strict in type-checking object properties.
404 Cyclic references in Scheme values for properties can cause hangs
408 * Constructing a tweak::
414 @node Constructing a tweak
415 @subsection Constructing a tweak
418 @cindex internal documentation
419 @cindex finding graphical objects
420 @cindex graphical object descriptions
422 @cindex @code{\override}
424 @cindex internal documentation
428 Three pieces of information are required to use @code{\override} and
429 @code{\set}: the name of the layout object, the context and the name
430 of the property. We demonstrate how to glean this information from
431 the notation manual and the program reference.
433 The generated documentation is a set of HTML pages which should be
434 included if you installed a binary distribution, typically in
435 @file{/usr/share/doc/lilypond}. They are also available on the web:
436 go to the @uref{http://lilypond.org,LilyPond website}, click
437 ``Documentation'', select the correct version, and then click
438 ``Program reference.'' It is advisable to bookmark the local HTML
439 files. They will load faster than the ones on the web and matches the
440 version of LilyPond you are using.
444 @c [TODO: revise for new site.]
446 Suppose we want to move the fingering indication in the fragment
449 @lilypond[relative=2,verbatim]
455 If you visit the documentation of @code{Fingering} (in @ref{Fingering
456 instructions}), you will notice that there is written:
461 Internals: @internalsref{FingerEvent} and @internalsref{Fingering}.
468 In other words, the fingerings once entered, are internally stored as
469 @code{FingerEvent} music objects. When printed, a @code{Fingering}
470 layout object is created for every @code{FingerEvent}.
472 The Fingering object has a number of different functions, and each of
473 those is captured in an interface. The interfaces are listed under
474 @internalsref{Fingering} in the program reference.
478 The @code{Fingering} object has a fixed size
479 (@internalsref{item-interface}), the symbol is a piece of text
480 (@internalsref{text-interface}), whose font can be set
481 (@internalsref{font-interface}). It is centered horizontally
482 (@internalsref{self-alignment-interface}), it is placed vertically
483 next to other objects (@internalsref{side-position-interface}), and
484 its placement is coordinated with other scripts
485 (@internalsref{text-script-interface}). It also has the standard
486 @internalsref{grob-interface} (grob stands for Graphical object)
488 @cindex graphical object
489 @cindex layout object
490 @cindex object, layout
491 with all the variables that come with
492 it. Finally, it denotes a fingering instruction, so it has
493 @internalsref{finger-interface}.
495 For the vertical placement, we have to look under
496 @code{side-position-interface}:
498 @code{side-position-interface}
500 Position a victim object (this one) next to other objects (the
501 support). In this case, the property @code{direction} signifies where to put the
502 victim object relative to the support (left or right, up or down?)
507 below this description, the variable @code{padding} is described as
511 (dimension, in staff space)
513 add this much extra space between objects that are next to each
514 other. Default value: @code{0.6}
518 By increasing the value of @code{padding}, we can move away the
519 fingering. The following command inserts 3 staff spaces of white
520 between the note and the fingering:
522 \once \override Fingering #'padding = #3
525 Inserting this command before the Fingering object is created,
526 i.e. before @code{c2}, yields the following result:
528 @lilypond[relative=2,fragment,verbatim]
529 \once \override Fingering
536 The context name @code{Voice} in the example above can be determined
537 as follows. In the documentation for @internalsref{Fingering}, it says
539 Fingering grobs are created by: @internalsref{Fingering_engraver} @c
542 Clicking @code{Fingering_engraver} shows the documentation of
543 the module responsible for interpreting the fingering instructions and
544 translating them to a @code{Fingering} object. Such a module is called
545 an @emph{engraver}. The documentation of the @code{Fingering_engraver}
548 Fingering_engraver is part of contexts: Voice
550 so tuning the settings for Fingering should be done with
552 \override Fingering @dots{}
555 Of course, the tweak may also done in a larger context than
556 @code{Voice}, for example, @internalsref{Staff} or
557 @internalsref{Score}.
561 Internals: the program reference also contains alphabetical lists of
562 @internalsref{Contexts}, @internalsref{All-layout-objects} and
563 @internalsref{Music-expressions}, so you can also find which objects
564 to tweak by browsing the internals document.
567 @node Selecting font sizes
568 @subsection Selecting font sizes
570 The most common thing to change about the appearance of fonts is their
571 size. The font size of any context can be easily changed by setting
572 the @code{fontSize} property for that context. Its value is a number:
573 negative numbers make the font smaller, positive numbers larger. An
574 example is given below:
576 @lilypond[fragment,relative=1,verbatim]
577 c4 c4 \set fontSize = #-3
580 This command will set @code{font-size} (see below) in all layout
581 objects in the current context. It does not change the size of
582 variable symbols, such as beams or slurs.
584 The font size is set by modifying the @code{font-size} property. Its
585 value is a number indicating the size relative to the standard size.
586 Each step up is an increase of approximately 12% of the font size. Six
587 steps is exactly a factor two. The Scheme function @code{magstep}
588 converts a @code{font-size} number to a scaling factor.
590 LilyPond has fonts in different design sizes: the music fonts for
591 smaller sizes are chubbier, while the text fonts are relatively wider.
592 Font size changes are achieved by scaling the design size that is
593 closest to the desired size.
595 The @code{font-size} mechanism does not work for fonts selected
596 through @code{font-name}. These may be scaled with
597 @code{font-magnification}.
600 One of the uses of @code{fontSize} is to get smaller symbols for cue
601 notes. An elaborate example of those is in
602 @inputfileref{input/test,cue-notes.ly}.
604 @cindex @code{font-style}
608 The following commands set @code{fontSize} for the current voice.
612 @cindex @code{\small}
614 @cindex @code{\normalsize}
619 @cindex magnification
624 @subsection Font selection
626 Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
627 can also be adjusted with a more fine-grained mechanism. By setting
628 the object properties described below, you can select a different font;
629 all three mechanisms work for every object that supports
630 @code{font-interface}:
634 @item @code{font-family}
635 is a symbol indicating the general class of the typeface. Supported are
636 @code{roman} (Computer Modern), @code{braces} (for piano staff
637 braces), @code{music} (the standard music font, including ancient
638 glyphs), @code{dynamic} (for dynamic signs) and @code{typewriter}.
640 @item @code{font-shape}
641 is a symbol indicating the shape of the font, there are typically several
642 font shapes available for each font family. Choices are @code{italic},
643 @code{caps} and @code{upright}.
645 @item @code{font-series}
646 is a symbol indicating the series of the font. There are typically several
647 font series for each font family and shape. Choices are @code{medium}
653 Fonts selected in the way sketched above come from a predefined style
656 The font used for printing a object can be selected by setting
657 @code{font-name}, e.g.
659 \override Staff.TimeSignature
660 #'font-name = #"cmr17"
664 Any font can be used, as long as it is available to @TeX{}. Possible
665 fonts include foreign fonts or fonts that do not belong to the
666 Computer Modern font family. The size of fonts selected in this way
667 can be changed with the @code{font-magnification} property. For
668 example, @code{2.0} blows up all letters by a factor 2 in both
672 @cindex font magnification
678 Init files: @file{ly/declarations-init.ly} contains hints how new
679 fonts may be added to LilyPond.
683 No style sheet is provided for other fonts besides the @TeX{}
684 Computer Modern family.
686 @cindex font selection
687 @cindex font magnification
688 @cindex @code{font-interface}
699 LilyPond has an internal mechanism to typeset texts. You can access it
700 with the keyword @code{\markup}. Within markup mode, you can enter texts
701 similar to lyrics: simply enter them, surrounded by spaces:
704 @lilypond[verbatim,fragment,relative=1]
706 c1_\markup { hi there }
707 c1^\markup { hi \bold there, is \italic anyone home? }
710 @cindex font switching
712 The markup in the example demonstrates font switching commands. The
713 command @code{\bold} and @code{\italic} only apply to the first
714 following word; enclose a set of texts with braces to apply a command
717 \markup @{ \bold @{ hi there @} @}
721 For clarity, you can also do this for single arguments, e.g.
724 \markup { is \italic { anyone } home }
727 @cindex font size, texts
730 In markup mode you can compose expressions, similar to mathematical
731 expressions, XML documents and music expressions. The braces group
732 notes into horizontal lines. Other types of lists also exist: you can
733 stack expressions grouped with @code{<}, and @code{>} vertically with
734 the command @code{\column}. Similarly, @code{\center-align} aligns
735 texts by their center lines:
737 @lilypond[verbatim,fragment,relative=1]
738 c1^\markup { \column < a bbbb c > }
739 c1^\markup { \center-align < a bbbb c > }
740 c1^\markup { \line < a b c > }
744 Markups can be stored in variables, and these variables
745 may be attached to notes, like
747 allegro = \markup { \bold \large { Allegro } }
748 \notes { a^\allegro b c d }
752 Some objects have alignment procedures of their own, which cancel out
753 any effects of alignments applied to their markup arguments as a
754 whole. For example, the @internalsref{RehearsalMark} is horizontally
755 centered, so using @code{\mark \markup @{ \left-align .. @}} has no
758 Similarly, for moving whole texts over notes with
759 @code{\raise}, use the following trick:
761 "" \raise #0.5 raised
764 The text @code{raised} is now raised relative to the empty string
765 @code{""} which is not visible. Alternatively, complete objects can
766 be moved with layout properties such as @code{padding} and
773 Init files: @file{scm/new-markup.scm}.
778 Text layout is ultimately done by @TeX{}, which does kerning of
779 letters. LilyPond does not account for kerning, so texts will be
780 spaced slightly too wide.
782 Syntax errors for markup mode are confusing.
784 Markup texts cannot be used in the titling of the @code{\header}
785 field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
791 * Overview of text markup commands::
794 @node Overview of text markup commands
795 @subsection Overview of text markup commands
797 @include markup-commands.tely
801 @section Global layout
803 The global layout determined by three factors: the page layout, the
804 line breaks and the spacing. These all influence each other. The
805 choice of spacing determines how densely each system of music is set,
806 which influences where line breaks breaks are chosen, and thus
807 ultimately how many pages a piece of music takes. This section
808 explains how to tune the algorithm for spacing.
810 Globally spoken, this procedure happens in three steps: first,
811 flexible distances (``springs'') are chosen, based on durations. All
812 possible line breaking combination are tried, and the one with the
813 best results---a layout that has uniform density and requires as
814 little stretching or cramping as possible---is chosen. When the score
815 is processed by @TeX{}, each page is filled with systems, and page breaks
816 are chosen whenever the page gets full.
822 * Horizontal spacing::
829 @node Vertical spacing
830 @subsection Vertical spacing
832 @cindex vertical spacing
833 @cindex distance between staves
834 @cindex staff distance
835 @cindex between staves, distance
836 @cindex staves per page
837 @cindex space between staves
839 The height of each system is determined automatically by LilyPond, to
840 keep systems from bumping into each other, some minimum distances are
841 set. By changing these, you can put staves closer together, and thus
842 put more systems onto one page.
844 Normally staves are stacked vertically. To make
845 staves maintain a distance, their vertical size is padded. This is
846 done with the property @code{minimumVerticalExtent}. It takes a pair
847 of numbers, so if you want to make it smaller from its, then you could
850 \set Staff.minimumVerticalExtent = #'(-4 . 4)
852 This sets the vertical size of the current staff to 4 staff spaces on
853 either side of the center staff line. The argument of
854 @code{minimumVerticalExtent} is interpreted as an interval, where the
855 center line is the 0, so the first number is generally negative. The
856 staff can be made larger at the bottom by setting it to @code{(-6
859 The piano staves are handled a little differently: to make cross-staff
860 beaming work correctly, it is necessary that the distance between staves
861 is fixed beforehand. This is also done with a
862 @internalsref{VerticalAlignment} object, created in
863 @internalsref{PianoStaff}. In this object the distance between the
864 staves is fixed by setting @code{forced-distance}. If you want to
865 override this, use a @code{\context} block as follows:
870 \override VerticalAlignment #'forced-distance = #9
875 This would bring the staves together at a distance of 9 staff spaces,
876 measured from the center line of each staff.
880 Internals: Vertical alignment of staves is handled by the
881 @internalsref{VerticalAlignment} object.
886 @node Horizontal spacing
887 @subsection Horizontal Spacing
889 The spacing engine translates differences in durations into
890 stretchable distances (``springs'') of differing lengths. Longer
891 durations get more space, shorter durations get less. The shortest
892 durations get a fixed amount of space (which is controlled by
893 @code{shortest-duration-space} in the @internalsref{SpacingSpanner} object).
894 The longer the duration, the more space it gets: doubling a
895 duration adds a fixed amount (this amount is controlled by
896 @code{spacing-increment}) of space to the note.
898 For example, the following piece contains lots of half, quarter and
899 8th notes, the eighth note is followed by 1 note head width (NHW).
900 The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
901 @lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8
905 Normally, @code{shortest-duration-space} is set to 1.2, which is the
906 width of a note head, and @code{shortest-duration-space} is set to
907 2.0, meaning that the shortest note gets 2 NHW (i.e. 2 times
908 @code{shortest-duration-space}) of space. For normal notes, this space
909 is always counted from the left edge of the symbol, so the shortest
910 notes are generally followed by one NHW of space.
912 If one would follow the above procedure exactly, then adding a single
913 32th note to a score that uses 8th and 16th notes, would widen up the
914 entire score a lot. The shortest note is no longer a 16th, but a 32nd,
915 thus adding 1 NHW to every note. To prevent this, the
916 shortest duration for spacing is not the shortest note in the score,
917 but the most commonly found shortest note. Notes that are even
918 shorter this are followed by a space that is proportional to their
919 duration relative to the common shortest note. So if we were to add
920 only a few 16th notes to the example above, they would be followed by
923 @lilypond[fragment,verbatim,relative=2]
924 c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4
927 The most common shortest duration is determined as follows: in every
928 measure, the shortest duration is determined. The most common short
929 duration, is taken as the basis for the spacing, with the stipulation
930 that this shortest duration should always be equal to or shorter than
931 1/8th note. The shortest duration is printed when you run lilypond
932 with @code{--verbose}. These durations may also be customized. If you
933 set the @code{common-shortest-duration} in
934 @internalsref{SpacingSpanner}, then this sets the base duration for
935 spacing. The maximum duration for this base (normally 1/8th), is set
936 through @code{base-shortest-duration}.
938 @cindex @code{common-shortest-duration}
939 @cindex @code{base-shortest-duration}
940 @cindex @code{stem-spacing-correction}
941 @cindex @code{spacing}
943 In the introduction it was explained that stem directions influence
944 spacing. This is controlled with @code{stem-spacing-correction}
945 property in @internalsref{NoteSpacing}, which are generated for every
946 @internalsref{Voice} context. The @code{StaffSpacing} object
947 (generated at @internalsref{Staff} context) contains the same property
948 for controlling the stem/bar line spacing. The following example
949 shows these corrections, once with default settings, and once with
950 exaggerated corrections:
956 \override Staff.NoteSpacing #'stem-spacing-correction
958 \override Staff.StaffSpacing #'stem-spacing-correction
963 \paper { raggedright = ##t } }
966 @cindex SpacingSpanner, overriding properties
968 Properties of the @internalsref{SpacingSpanner} must be overridden
969 from the @code{\paper} block, since the @internalsref{SpacingSpanner} is
970 created before any property commands are interpreted.
972 \paper @{ \context @{
974 SpacingSpanner \override #'spacing-increment = #3.0
981 Internals: @internalsref{SpacingSpanner}, @internalsref{NoteSpacing},
982 @internalsref{StaffSpacing}, @internalsref{SeparationItem}, and
983 @internalsref{SeparatingGroupSpanner}.
987 Spacing is determined on a score wide basis. If you have a score that
988 changes its character (measured in durations) halfway during the
989 score, the part containing the longer durations will be spaced too
992 There is no convenient mechanism to manually override spacing.
997 @subsection Font size
999 @cindex font size, setting
1000 @cindex staff size, setting
1001 @cindex @code{paper} file
1003 The Feta font provides musical symbols at eight different
1004 sizes. Each font is tuned for a different staff size: at smaller sizes
1005 the font gets heavier, to match the relatively heavier staff lines.
1006 The recommended font sizes are listed in the following table:
1008 @multitable @columnfractions .25 .25 .25 .25
1011 @tab @b{staff height (pt)}
1012 @tab @b{staff height (mm)}
1054 @c modern rental material ?
1058 These fonts are available in any sizes. The context property
1059 @code{fontSize} and the layout property @code{staff-space} (in
1060 @internalsref{StaffSymbol}) can be used to tune size for individual
1061 staves. The size of individual staves are relative to the global size,
1062 which can be set in the following manner:
1065 #(set-global-staff-size 14)
1068 This sets the global default size to 14pt staff height, and scales all
1073 This manual: @ref{Selecting font sizes}.
1077 @subsection Line breaking
1080 @cindex breaking lines
1082 Line breaks are normally computed automatically. They are chosen such
1083 that lines look neither cramped nor loose, and that consecutive lines
1084 have similar density.
1086 Occasionally you might want to override the automatic breaks; you can
1087 do this by specifying @code{\break}. This will force a line break at
1088 this point. Line breaks can only occur at places where there are bar
1089 lines. If you want to have a line break where there is no bar line,
1090 you can force an invisible bar line by entering @code{\bar
1091 ""}. Similarly, @code{\noBreak} forbids a line break at a
1095 @cindex regular line breaks
1096 @cindex four bar music.
1098 For line breaks at regular intervals use @code{\break} separated by
1099 skips and repeated with @code{\repeat}:
1101 << \repeat unfold 7 @{
1102 s1 \noBreak s1 \noBreak
1103 s1 \noBreak s1 \break @}
1104 @emph{the real music}
1109 This makes the following 28 measures (assuming 4/4 time) be broken every
1110 4 measures, and only there.
1114 @code{\break}, @code{\noBreak}
1115 @cindex @code{\break}
1116 @cindex @code{\noBreak}
1120 Internals: @internalsref{BreakEvent}.
1124 @subsection Page layout
1127 @cindex breaking pages
1129 @cindex @code{indent}
1130 @cindex @code{linewidth}
1132 The most basic settings influencing the spacing are @code{indent} and
1133 @code{linewidth}. They are set in the @code{\paper} block. They
1134 control the indentation of the first line of music, and the lengths of
1137 If @code{raggedright} is set to true in the @code{\paper}
1138 block, then the lines are justified at their natural length. This
1139 useful for short fragments, and for checking how tight the natural
1143 @cindex vertical spacing
1145 The page layout process happens outside the LilyPond formatting
1146 engine: variables controlling page layout are passed to the output,
1147 and are further interpreted by @code{lilypond} wrapper program. It
1148 responds to the following variables in the @code{\paper} block. The
1149 spacing between systems is controlled with @code{interscoreline}, its
1150 default is 16pt. The distance between the score lines will stretch in
1151 order to fill the full page @code{interscorelinefill} is set to a
1152 positive number. In that case @code{interscoreline} specifies the
1155 @cindex @code{textheight}
1156 @cindex @code{interscoreline}
1157 @cindex @code{interscorelinefill}
1159 If the variable @code{lastpagefill} is defined,
1160 @c fixme: this should only be done if lastpagefill= #t
1161 systems are evenly distributed vertically on the last page. This
1162 might produce ugly results in case there are not enough systems on the
1163 last page. The @command{lilypond-book} command ignores
1164 @code{lastpagefill}. See @ref{lilypond-book manual} for more
1167 @cindex @code{lastpagefill}
1169 Page breaks are normally computed by @TeX{}, so they are not under
1170 direct control of LilyPond. However, you can insert a commands into
1171 the @file{.tex} output to instruct @TeX{} where to break pages. This
1172 is done by setting the @code{between-systems-strings} on the
1173 @internalsref{NonMusicalPaperColumn} where the system is broken.
1174 An example is shown in @inputfileref{input/regression,between-systems.ly}.
1175 The predefined command @code{\newpage} also does this.
1179 @cindex @code{papersize}
1181 To change the paper size, use the following Scheme code:
1184 #(set-paper-size "a4")
1191 @cindex @code{\newpage}
1197 In this manual: @ref{Invoking lilypond}.
1199 Examples: @inputfileref{input/regression,between-systems.ly}.
1201 Internals: @internalsref{NonMusicalPaperColumn}.
1205 LilyPond has no concept of page layout, which makes it difficult to
1206 reliably choose page breaks in longer pieces.
1209 @node Interpretation context
1210 @section Interpretation context
1213 * Creating contexts::
1214 * Default contexts::
1215 * Context properties::
1216 * Defining contexts::
1217 * Changing contexts locally::
1218 * Engravers and performers::
1219 * Defining new contexts::
1223 Interpretation contexts are objects that only exist during program
1224 run. During the interpretation phase (when @code{interpreting music}
1225 is printed on the standard output), the music expression in a
1226 @code{\score} block is interpreted in time order, the same order in
1227 which we hear and play the music. During this phase, the interpretation
1228 context holds the state for the current point within the music, for
1231 @item What notes are playing at this point?
1233 @item What symbols will be printed at this point?
1235 @item What is the current key signature, time signature, point within
1239 Contexts are grouped hierarchically: A @internalsref{Voice} context is
1240 contained in a @internalsref{Staff} context (because a staff can contain
1241 multiple voices at any point), a @internalsref{Staff} context is contained in
1242 @internalsref{Score}, @internalsref{StaffGroup}, or
1243 @internalsref{ChoirStaff} context.
1245 Contexts associated with sheet music output are called @emph{notation
1246 contexts}, those for sound output are called @emph{performance
1247 contexts}. The default definitions of the standard notation and
1248 performance contexts can be found in @file{ly/engraver-init.ly} and
1249 @file{ly/performer-init.ly}, respectively.
1252 @node Creating contexts
1253 @subsection Creating contexts
1254 @cindex @code{\context}
1255 @cindex context selection
1257 Contexts for a music expression can be selected manually, using one of
1258 the following music expressions:
1261 \new @var{contexttype} @var{musicexpr}
1262 \context @var{contexttype} [= @var{contextname}] @var{musicexpr}
1266 This means that @var{musicexpr} should be interpreted within a context
1267 of type @var{contexttype} (with name @var{contextname} if specified).
1268 If no such context exists, it will be created:
1270 @lilypond[verbatim,raggedright]
1272 \notes \relative c'' {
1273 c4 <<d4 \context Staff = "another" e4>> f
1279 In this example, the @code{c} and @code{d} are printed on the default
1280 staff. For the @code{e}, a context @code{Staff} called @code{another}
1281 is specified; since that does not exist, a new context is created.
1282 Within @code{another}, a (default) Voice context is created for the
1283 @code{e4}. A context is ended when when all music referring it has
1284 finished, so after the third quarter, @code{another} is removed.
1286 The @code{\new} construction creates a context with a
1287 generated, unique @var{contextname}. An expression with
1288 @code{\new} always leads to a new context. This is convenient
1289 for creating multiple staves, multiple lyric lines, etc.
1291 When using automatic staff changes, automatic phrasing, etc., the
1292 context names have special meanings, so @code{\new} cannot be
1296 @node Default contexts
1297 @subsection Default contexts
1299 Every top level music is interpreted by the @code{Score} context; in
1300 other words, you may think of @code{\score} working like
1304 \context Score @var{music}
1308 Music expressions inherit their context from the enclosing music
1309 expression. Hence, it is not necessary to explicitly specify
1310 @code{\context} for most expressions. In
1311 the following example, only the sequential expression has an explicit
1312 context. The notes contained therein inherit the @code{goUp} context
1313 from the enclosing music expression.
1315 @lilypond[verbatim,raggedright]
1316 \notes \context Voice = goUp { c'4 d' e' }
1320 Second, contexts are created automatically to be able to interpret the
1321 music expressions. Consider the following example:
1323 @lilypond[verbatim,raggedright]
1324 \score { \notes { c'4-( d' e'-) } }
1328 The sequential music is interpreted by the Score context initially,
1329 but when a note is encountered, contexts are setup to accept that
1330 note. In this case, a @code{Voice}, and @code{Staff}
1331 context are created. The rest of the sequential music is also
1332 interpreted with the same @code{Voice}, and
1333 @code{Staff} context, putting the notes on the same staff, in the same
1336 @node Context properties
1337 @subsection Context properties
1339 Contexts have properties. These properties are set from the @file{.ly}
1340 file using the following expression:
1341 @cindex context properties
1342 @cindex properties, context
1345 \set @var{contextname}.@var{propname} = @var{value}
1349 Sets the @var{propname} property of the context @var{contextname} to
1350 the specified Scheme expression @var{value}. Both @var{propname} and
1351 @var{contextname} are strings, which can often be written unquoted.
1354 Properties that are set in one context are inherited by all of the
1355 contained contexts. This means that a property valid for the
1356 @internalsref{Voice} context can be set in the @internalsref{Score} context
1357 (for example) and thus take effect in all @internalsref{Voice} contexts.
1359 Properties can be unset using the following statement.
1361 \unset @var{contextname}.@var{propname}
1364 @cindex properties, unsetting
1365 @cindex @code{\unset}
1368 This removes the definition of @var{propname} in @var{contextname}. If
1369 @var{propname} was not defined in @var{contextname} (but was inherited
1370 from a higher context), then this has no effect.
1372 If @var{contextname} is left out, then it defaults to the current
1373 ``bottom'' context: this is a context like @internalsref{Voice} that
1374 cannot contain any other contexts.
1377 @node Defining contexts
1378 @subsection Defining contexts
1380 @cindex context definition
1381 @cindex translator definition
1383 The most common way to create a new context definition is by extending
1384 an existing one. An existing context from the paper block is copied
1385 by referencing a context identifier:
1390 @var{context-identifier}
1396 Every predefined context has a standard identifier. For example, the
1397 @code{Staff} context can be referred to as @code{\StaffContext}.
1399 The context can then be modified by setting or changing properties,
1404 Stem \set #'thickness = #2.0
1405 defaultBarType = #"||"
1408 These assignments happen before interpretation starts, so a property
1409 command will override any predefined settings.
1415 It is not possible to collect multiple property assignments in a
1416 variable, and apply to one @code{\context} definition by
1417 referencing that variable.
1419 @node Changing contexts locally
1420 @subsection Changing contexts locally
1423 Extending an existing context can also be done locally. A piece of
1424 music can be interpreted in a changed context by using the following syntax
1428 @var{context modifications}
1432 These statements comes between @code{\new} or @code{\context} and the
1433 music to be interpreted. The @var{context modifications} property
1434 settings and @code{\remove}, @code{\consists} and @code{\consistsend}
1435 commands. The syntax is similar to the @code{\context} block.
1437 The following example shows how a staff is created with bigger spaces,
1438 and without a @code{Clef_engraver}.
1440 @lilypond[relative=1,fragment,verbatim]
1442 \new Staff { c4 es4 g2 }
1444 \override StaffSymbol #'staff-space = #(magstep 1.5)
1446 \remove "Clef_engraver"
1454 The command @code{\with} has no effect on contexts that already
1458 @node Engravers and performers
1459 @subsection Engravers and performers
1462 Each context is composed of a number of building blocks, or plug-ins
1463 called engravers. An engraver is a specialized C++ class that is
1464 compiled into the executable. Typically, an engraver is responsible
1465 for one function: the @code{Slur_engraver} creates only @code{Slur}
1466 objects, and the @code{Skip_event_swallow_translator} only swallows
1467 (silently gobbles) @code{SkipEvent}s.
1474 An existing context definition can be changed by adding or removing an
1475 engraver. The syntax for these operations is
1477 \consists @var{engravername}
1478 \remove @var{engravername}
1481 @cindex @code{\consists}
1482 @cindex @code{\remove}
1485 Here @var{engravername} is a string, the name of an engraver in the
1486 system. In the following example, the @code{Clef_engraver} is removed
1487 from the Staff context. The result is a staff without a clef, where
1488 the middle C is at its default position, the center line:
1490 @lilypond[verbatim,raggedright]
1498 \remove Clef_engraver
1504 A list of all engravers is in the internal documentation,
1505 see @internalsref{Engravers}.
1507 @node Defining new contexts
1508 @subsection Defining new contexts
1511 It is also possible to define new contexts from scratch. To do this,
1512 you must define give the new context a name. In the following
1513 example, a very simple Staff context is created: one that will put
1514 note heads on a staff symbol.
1518 \type "Engraver_group_engraver"
1521 \consists "Staff_symbol_engraver"
1522 \consists "Note_head_engraver"
1523 \consistsend "Axis_group_engraver"
1528 The argument of @code{\type} is the name for a special engraver that
1529 handles cooperation between simple engravers such as
1530 @code{Note_head_engraver} and @code{Staff_symbol_engraver}. This
1531 should always be @code{Engraver_group_engraver} (unless you are
1532 defining a Score context from scratch, in which case
1533 @code{Score_engraver} must be used).
1535 The complete list of context modifiers is the following:
1537 @item @code{\alias} @var{alternate-name}:
1538 This specifies a different name. In the above example,
1539 @code{\set Staff.X = Y} will also work on @code{SimpleStaff}s.
1541 @item @code{\consistsend} @var{engravername}:
1542 Analogous to @code{\consists}, but makes sure that
1543 @var{engravername} is always added to the end of the list of
1546 Engravers that group context objects into axis groups or alignments
1547 need to be at the end of the list. @code{\consistsend} insures that
1548 engravers stay at the end even if a user adds or removes engravers.
1550 @item @code{\accepts} @var{contextname}:
1551 This context can contains @var{contextname} contexts. The first
1552 @code{\accepts} is created as a default context when events (e.g. notes
1553 or rests) are encountered.
1555 @item @code{\denies}:
1556 The opposite of @code{\accepts}.
1558 @item @code{\name} @var{contextname}:
1559 This sets the type name of the context, e.g. @code{Staff},
1560 @code{Voice}. If the name is not specified, the translator will not
1569 @node Output details
1570 @section Output details
1572 The default output format is La@TeX{}, which should be run
1573 through La@TeX{}. Using the option @option{-f}
1574 (or @option{--format}) other output formats can be selected also, but
1575 none of them work reliably.
1577 At the beginning of the output file, various global parameters are
1578 defined. Then the file @file{lilyponddefs.tex} is loaded to define
1579 the macros used in the code which follows. @file{lilyponddefs.tex}
1580 includes various other files, partially depending on the global
1583 Now the music is output system by system (a `system' consists of all
1584 staves belonging together). From @TeX{}'s point of view, a system is an
1585 @code{\hbox} which contains a lowered @code{\vbox} so that it is centered
1586 vertically on the baseline of the text. Between systems,
1587 @code{\interscoreline} is inserted vertically to have stretchable space.
1588 The horizontal dimension of the @code{\hbox} is given by the
1589 @code{linewidth} parameter from LilyPond's @code{\paper} block.
1591 After the last system LilyPond emits a stronger variant of
1592 @code{\interscoreline} only if the macro
1593 @code{\lilypondpaperlastpagefill} is not defined (flushing the systems
1594 to the top of the page). You can avoid that by setting the variable
1595 @code{lastpagefill} in LilyPond's @code{\paper} block.
1597 It is possible to fine-tune the vertical offset further by defining the
1598 macro @code{\lilypondscoreshift}:
1601 \def\lilypondscoreshift@{0.25\baselineskip@}
1605 where @code{\baselineskip} is the distance from one text line to the next.
1607 Here an example how to embed a small LilyPond file @code{foo.ly} into
1608 running La@TeX{} text without using the @code{lilypond-book} script
1609 (@pxref{lilypond-book manual}):
1612 \documentclass@{article@}
1614 \def\lilypondpaperlastpagefill@{@}
1616 \def\lilypondscoreshift@{0.25\baselineskip@}
1619 This is running text which includes an example music file
1625 The file @file{foo.tex} has been simply produced with
1631 The call to @code{\lineskip} assures that there is enough vertical space
1632 between the LilyPond box and the surrounding text lines.