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 @node Constructing a tweak
409 @subsection Constructing a tweak
412 @cindex internal documentation
413 @cindex finding graphical objects
414 @cindex graphical object descriptions
416 @cindex @code{\override}
418 @cindex internal documentation
422 Three pieces of information are required to use @code{\override} and
423 @code{\set}: the name of the layout object, the context and the name
424 of the property. We demonstrate how to glean this information from
425 the notation manual and the program reference.
427 The generated documentation is a set of HTML pages which should be
428 included if you installed a binary distribution, typically in
429 @file{/usr/share/doc/lilypond}. They are also available on the web:
430 go to the @uref{http://lilypond.org,LilyPond website}, click
431 ``Documentation'', select the correct version, and then click
432 ``Program reference.'' It is advisable to bookmark the local HTML
433 files. They will load faster than the ones on the web and matches the
434 version of LilyPond you are using.
438 @c [TODO: revise for new site.]
440 Suppose we want to move the fingering indication in the fragment
443 @lilypond[relative=2,verbatim]
449 If you visit the documentation of @code{Fingering} (in @ref{Fingering
450 instructions}), you will notice that there is written:
455 Internals: @internalsref{FingerEvent} and @internalsref{Fingering}.
462 In other words, the fingerings once entered, are internally stored as
463 @code{FingerEvent} music objects. When printed, a @code{Fingering}
464 layout object is created for every @code{FingerEvent}.
466 The Fingering object has a number of different functions, and each of
467 those is captured in an interface. The interfaces are listed under
468 @internalsref{Fingering} in the program reference.
472 The @code{Fingering} object has a fixed size
473 (@internalsref{item-interface}), the symbol is a piece of text
474 (@internalsref{text-interface}), whose font can be set
475 (@internalsref{font-interface}). It is centered horizontally
476 (@internalsref{self-alignment-interface}), it is placed vertically
477 next to other objects (@internalsref{side-position-interface}), and
478 its placement is coordinated with other scripts
479 (@internalsref{text-script-interface}). It also has the standard
480 @internalsref{grob-interface} (grob stands for Graphical object)
482 @cindex graphical object
483 @cindex layout object
484 @cindex object, layout
485 with all the variables that come with
486 it. Finally, it denotes a fingering instruction, so it has
487 @internalsref{finger-interface}.
489 For the vertical placement, we have to look under
490 @code{side-position-interface}:
492 @code{side-position-interface}
494 Position a victim object (this one) next to other objects (the
495 support). In this case, the property @code{direction} signifies where to put the
496 victim object relative to the support (left or right, up or down?)
501 below this description, the variable @code{padding} is described as
505 (dimension, in staff space)
507 add this much extra space between objects that are next to each
508 other. Default value: @code{0.6}
512 By increasing the value of @code{padding}, we can move away the
513 fingering. The following command inserts 3 staff spaces of white
514 between the note and the fingering:
516 \once \override Fingering #'padding = #3
519 Inserting this command before the Fingering object is created,
520 i.e. before @code{c2}, yields the following result:
522 @lilypond[relative=2,fragment,verbatim]
523 \once \override Fingering
530 The context name @code{Voice} in the example above can be determined
531 as follows. In the documentation for @internalsref{Fingering}, it says
533 Fingering grobs are created by: @internalsref{Fingering_engraver} @c
536 Clicking @code{Fingering_engraver} shows the documentation of
537 the module responsible for interpreting the fingering instructions and
538 translating them to a @code{Fingering} object. Such a module is called
539 an @emph{engraver}. The documentation of the @code{Fingering_engraver}
542 Fingering_engraver is part of contexts: Voice
544 so tuning the settings for Fingering should be done with
546 \override Fingering @dots{}
549 Of course, the tweak may also done in a larger context than
550 @code{Voice}, for example, @internalsref{Staff} or
551 @internalsref{Score}.
555 Internals: the program reference also contains alphabetical lists of
556 @internalsref{Contexts}, @internalsref{All-layout-objects} and
557 @internalsref{Music-expressions}, so you can also find which objects
558 to tweak by browsing the internals document.
561 @node Selecting font sizes
562 @subsection Selecting font sizes
564 The most common thing to change about the appearance of fonts is their
565 size. The font size of any context can be easily changed by setting
566 the @code{fontSize} property for that context. Its value is a number:
567 negative numbers make the font smaller, positive numbers larger. An
568 example is given below:
570 @lilypond[fragment,relative=1,verbatim]
571 c4 c4 \set fontSize = #-3
574 This command will set @code{font-size} (see below) in all layout
575 objects in the current context. It does not change the size of
576 variable symbols, such as beams or slurs.
578 The font size is set by modifying the @code{font-size} property. Its
579 value is a number indicating the size relative to the standard size.
580 Each step up is an increase of approximately 12% of the font size. Six
581 steps is exactly a factor two. The Scheme function @code{magstep}
582 converts a @code{font-size} number to a scaling factor.
584 LilyPond has fonts in different design sizes: the music fonts for
585 smaller sizes are chubbier, while the text fonts are relatively wider.
586 Font size changes are achieved by scaling the design size that is
587 closest to the desired size.
589 The @code{font-size} mechanism does not work for fonts selected
590 through @code{font-name}. These may be scaled with
591 @code{font-magnification}.
594 One of the uses of @code{fontSize} is to get smaller symbols for cue
595 notes. An elaborate example of those is in
596 @inputfileref{input/test,cue-notes.ly}.
598 @cindex @code{font-style}
602 The following commands set @code{fontSize} for the current voice.
606 @cindex @code{\small}
608 @cindex @code{\normalsize}
613 @cindex magnification
618 @subsection Font selection
620 Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
621 can also be adjusted with a more fine-grained mechanism. By setting
622 the object properties described below, you can select a different font;
623 all three mechanisms work for every object that supports
624 @code{font-interface}:
628 @item @code{font-encoding}
629 is a symbol that sets layout of the glyphs. Choices include
630 @code{text} for normal text, @code{braces} (for piano staff braces),
631 @code{music} (the standard music font, including ancient glyphs),
632 @code{dynamic} (for dynamic signs) and @code{number} for the number
636 @item @code{font-family}
637 is a symbol indicating the general class of the typeface. Supported are
638 @code{roman} (Computer Modern), @code{sans} and @code{typewriter}
640 @item @code{font-shape}
641 is a symbol indicating the shape of the font, there are typically
642 several font shapes available for each font family. Choices are
643 @code{italic}, @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}
652 Fonts selected in the way sketched above come from a predefined style
655 The font used for printing a object can be selected by setting
656 @code{font-name}, e.g.
658 \override Staff.TimeSignature
659 #'font-name = #"cmr17"
663 Any font can be used, as long as it is available to @TeX{}. Possible
664 fonts include foreign fonts or fonts that do not belong to the
665 Computer Modern font family. The size of fonts selected in this way
666 can be changed with the @code{font-magnification} property. For
667 example, @code{2.0} blows up all letters by a factor 2 in both
671 @cindex font magnification
677 Init files: @file{ly/declarations-init.ly} contains hints how new
678 fonts may be added to LilyPond.
682 No style sheet is provided for other fonts besides the @TeX{}
683 Computer Modern family.
685 @cindex font selection
686 @cindex font magnification
687 @cindex @code{font-interface}
698 LilyPond has an internal mechanism to typeset texts. You can access it
699 with the keyword @code{\markup}. Within markup mode, you can enter texts
700 similar to lyrics: simply enter them, surrounded by spaces:
703 @lilypond[verbatim,fragment,relative=1]
705 c1_\markup { hi there }
706 c1^\markup { hi \bold there, is \italic anyone home? }
709 @cindex font switching
711 The markup in the example demonstrates font switching commands. The
712 command @code{\bold} and @code{\italic} only apply to the first
713 following word; enclose a set of texts with braces to apply a command
716 \markup @{ \bold @{ hi there @} @}
720 For clarity, you can also do this for single arguments, e.g.
723 \markup { is \italic { anyone } home }
726 @cindex font size, texts
729 In markup mode you can compose expressions, similar to mathematical
730 expressions, XML documents and music expressions. The braces group
731 notes into horizontal lines. Other types of lists also exist: you can
732 stack expressions grouped with @code{<}, and @code{>} vertically with
733 the command @code{\column}. Similarly, @code{\center-align} aligns
734 texts by their center lines:
736 @lilypond[verbatim,fragment,relative=1]
737 c1^\markup { \column < a bbbb c > }
738 c1^\markup { \center-align < a bbbb c > }
739 c1^\markup { \line < a b c > }
743 Markups can be stored in variables, and these variables
744 may be attached to notes, like
746 allegro = \markup { \bold \large { Allegro } }
747 \notes { a^\allegro b c d }
751 Some objects have alignment procedures of their own, which cancel out
752 any effects of alignments applied to their markup arguments as a
753 whole. For example, the @internalsref{RehearsalMark} is horizontally
754 centered, so using @code{\mark \markup @{ \left-align .. @}} has no
757 Similarly, for moving whole texts over notes with
758 @code{\raise}, use the following trick:
760 "" \raise #0.5 raised
763 The text @code{raised} is now raised relative to the empty string
764 @code{""} which is not visible. Alternatively, complete objects can
765 be moved with layout properties such as @code{padding} and
772 Init files: @file{scm/new-markup.scm}.
777 Text layout is ultimately done by @TeX{}, which does kerning of
778 letters. LilyPond does not account for kerning, so texts will be
779 spaced slightly too wide.
781 Syntax errors for markup mode are confusing.
783 Markup texts cannot be used in the titling of the @code{\header}
784 field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
790 * Overview of text markup commands::
793 @node Overview of text markup commands
794 @subsection Overview of text markup commands
796 @include markup-commands.tely
800 @section Global layout
802 The global layout determined by three factors: the page layout, the
803 line breaks and the spacing. These all influence each other. The
804 choice of spacing determines how densely each system of music is set,
805 which influences where line breaks breaks are chosen, and thus
806 ultimately how many pages a piece of music takes. This section
807 explains how to tune the algorithm for spacing.
809 Globally spoken, this procedure happens in three steps: first,
810 flexible distances (``springs'') are chosen, based on durations. All
811 possible line breaking combination are tried, and the one with the
812 best results---a layout that has uniform density and requires as
813 little stretching or cramping as possible---is chosen. When the score
814 is processed by @TeX{}, each page is filled with systems, and page breaks
815 are chosen whenever the page gets full.
821 * Horizontal spacing::
828 @node Vertical spacing
829 @subsection Vertical spacing
831 @cindex vertical spacing
832 @cindex distance between staves
833 @cindex staff distance
834 @cindex between staves, distance
835 @cindex staves per page
836 @cindex space between staves
838 The height of each system is determined automatically by LilyPond, to
839 keep systems from bumping into each other, some minimum distances are
840 set. By changing these, you can put staves closer together, and thus
841 put more systems onto one page.
843 Normally staves are stacked vertically. To make
844 staves maintain a distance, their vertical size is padded. This is
845 done with the property @code{minimumVerticalExtent}. It takes a pair
846 of numbers, so if you want to make it smaller from its, then you could
849 \set Staff.minimumVerticalExtent = #'(-4 . 4)
851 This sets the vertical size of the current staff to 4 staff spaces on
852 either side of the center staff line. The argument of
853 @code{minimumVerticalExtent} is interpreted as an interval, where the
854 center line is the 0, so the first number is generally negative. The
855 staff can be made larger at the bottom by setting it to @code{(-6
858 The piano staves are handled a little differently: to make cross-staff
859 beaming work correctly, it is necessary that the distance between staves
860 is fixed beforehand. This is also done with a
861 @internalsref{VerticalAlignment} object, created in
862 @internalsref{PianoStaff}. In this object the distance between the
863 staves is fixed by setting @code{forced-distance}. If you want to
864 override this, use a @code{\context} block as follows:
869 \override VerticalAlignment #'forced-distance = #9
874 This would bring the staves together at a distance of 9 staff spaces,
875 measured from the center line of each staff.
879 Internals: Vertical alignment of staves is handled by the
880 @internalsref{VerticalAlignment} object.
885 @node Horizontal spacing
886 @subsection Horizontal Spacing
888 The spacing engine translates differences in durations into
889 stretchable distances (``springs'') of differing lengths. Longer
890 durations get more space, shorter durations get less. The shortest
891 durations get a fixed amount of space (which is controlled by
892 @code{shortest-duration-space} in the @internalsref{SpacingSpanner} object).
893 The longer the duration, the more space it gets: doubling a
894 duration adds a fixed amount (this amount is controlled by
895 @code{spacing-increment}) of space to the note.
897 For example, the following piece contains lots of half, quarter and
898 8th notes, the eighth note is followed by 1 note head width (NHW).
899 The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
900 @lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8
904 Normally, @code{shortest-duration-space} is set to 1.2, which is the
905 width of a note head, and @code{shortest-duration-space} is set to
906 2.0, meaning that the shortest note gets 2 NHW (i.e. 2 times
907 @code{shortest-duration-space}) of space. For normal notes, this space
908 is always counted from the left edge of the symbol, so the shortest
909 notes are generally followed by one NHW of space.
911 If one would follow the above procedure exactly, then adding a single
912 32th note to a score that uses 8th and 16th notes, would widen up the
913 entire score a lot. The shortest note is no longer a 16th, but a 32nd,
914 thus adding 1 NHW to every note. To prevent this, the
915 shortest duration for spacing is not the shortest note in the score,
916 but the most commonly found shortest note. Notes that are even
917 shorter this are followed by a space that is proportional to their
918 duration relative to the common shortest note. So if we were to add
919 only a few 16th notes to the example above, they would be followed by
922 @lilypond[fragment,verbatim,relative=2]
923 c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4
926 The most common shortest duration is determined as follows: in every
927 measure, the shortest duration is determined. The most common short
928 duration, is taken as the basis for the spacing, with the stipulation
929 that this shortest duration should always be equal to or shorter than
930 1/8th note. The shortest duration is printed when you run lilypond
931 with @code{--verbose}. These durations may also be customized. If you
932 set the @code{common-shortest-duration} in
933 @internalsref{SpacingSpanner}, then this sets the base duration for
934 spacing. The maximum duration for this base (normally 1/8th), is set
935 through @code{base-shortest-duration}.
937 @cindex @code{common-shortest-duration}
938 @cindex @code{base-shortest-duration}
939 @cindex @code{stem-spacing-correction}
940 @cindex @code{spacing}
942 In the introduction it was explained that stem directions influence
943 spacing. This is controlled with @code{stem-spacing-correction}
944 property in @internalsref{NoteSpacing}, which are generated for every
945 @internalsref{Voice} context. The @code{StaffSpacing} object
946 (generated at @internalsref{Staff} context) contains the same property
947 for controlling the stem/bar line spacing. The following example
948 shows these corrections, once with default settings, and once with
949 exaggerated corrections:
955 \override Staff.NoteSpacing #'stem-spacing-correction
957 \override Staff.StaffSpacing #'stem-spacing-correction
962 \paper { raggedright = ##t } }
965 @cindex SpacingSpanner, overriding properties
967 Properties of the @internalsref{SpacingSpanner} must be overridden
968 from the @code{\paper} block, since the @internalsref{SpacingSpanner} is
969 created before any property commands are interpreted.
971 \paper @{ \context @{
973 SpacingSpanner \override #'spacing-increment = #3.0
980 Internals: @internalsref{SpacingSpanner}, @internalsref{NoteSpacing},
981 @internalsref{StaffSpacing}, @internalsref{SeparationItem}, and
982 @internalsref{SeparatingGroupSpanner}.
986 Spacing is determined on a score wide basis. If you have a score that
987 changes its character (measured in durations) halfway during the
988 score, the part containing the longer durations will be spaced too
991 There is no convenient mechanism to manually override spacing.
996 @subsection Font size
998 @cindex font size, setting
999 @cindex staff size, setting
1000 @cindex @code{paper} file
1002 The Feta font provides musical symbols at eight different
1003 sizes. Each font is tuned for a different staff size: at smaller sizes
1004 the font gets heavier, to match the relatively heavier staff lines.
1005 The recommended font sizes are listed in the following table:
1007 @multitable @columnfractions .25 .25 .25 .25
1010 @tab @b{staff height (pt)}
1011 @tab @b{staff height (mm)}
1053 @c modern rental material ?
1057 These fonts are available in any sizes. The context property
1058 @code{fontSize} and the layout property @code{staff-space} (in
1059 @internalsref{StaffSymbol}) can be used to tune size for individual
1060 staves. The size of individual staves are relative to the global size,
1061 which can be set in the following manner:
1064 #(set-global-staff-size 14)
1067 This sets the global default size to 14pt staff height, and scales all
1072 This manual: @ref{Selecting font sizes}.
1076 @subsection Line breaking
1079 @cindex breaking lines
1081 Line breaks are normally computed automatically. They are chosen such
1082 that lines look neither cramped nor loose, and that consecutive lines
1083 have similar density.
1085 Occasionally you might want to override the automatic breaks; you can
1086 do this by specifying @code{\break}. This will force a line break at
1087 this point. Line breaks can only occur at places where there are bar
1088 lines. If you want to have a line break where there is no bar line,
1089 you can force an invisible bar line by entering @code{\bar
1090 ""}. Similarly, @code{\noBreak} forbids a line break at a
1094 @cindex regular line breaks
1095 @cindex four bar music.
1097 For line breaks at regular intervals use @code{\break} separated by
1098 skips and repeated with @code{\repeat}:
1100 << \repeat unfold 7 @{
1101 s1 \noBreak s1 \noBreak
1102 s1 \noBreak s1 \break @}
1103 @emph{the real music}
1108 This makes the following 28 measures (assuming 4/4 time) be broken every
1109 4 measures, and only there.
1113 @code{\break}, @code{\noBreak}
1114 @cindex @code{\break}
1115 @cindex @code{\noBreak}
1119 Internals: @internalsref{BreakEvent}.
1123 @subsection Page layout
1126 @cindex breaking pages
1128 @cindex @code{indent}
1129 @cindex @code{linewidth}
1131 The most basic settings influencing the spacing are @code{indent} and
1132 @code{linewidth}. They are set in the @code{\paper} block. They
1133 control the indentation of the first line of music, and the lengths of
1136 If @code{raggedright} is set to true in the @code{\paper}
1137 block, then the lines are justified at their natural length. This
1138 useful for short fragments, and for checking how tight the natural
1142 @cindex vertical spacing
1144 The page layout process happens outside the LilyPond formatting
1145 engine: variables controlling page layout are passed to the output,
1146 and are further interpreted by @code{lilypond} wrapper program. It
1147 responds to the following variables in the @code{\paper} block. The
1148 spacing between systems is controlled with @code{interscoreline}, its
1149 default is 16pt. The distance between the score lines will stretch in
1150 order to fill the full page @code{interscorelinefill} is set to a
1151 positive number. In that case @code{interscoreline} specifies the
1154 @cindex @code{textheight}
1155 @cindex @code{interscoreline}
1156 @cindex @code{interscorelinefill}
1158 If the variable @code{lastpagefill} is defined,
1159 @c fixme: this should only be done if lastpagefill= #t
1160 systems are evenly distributed vertically on the last page. This
1161 might produce ugly results in case there are not enough systems on the
1162 last page. The @command{lilypond-book} command ignores
1163 @code{lastpagefill}. See @ref{lilypond-book manual} for more
1166 @cindex @code{lastpagefill}
1168 Page breaks are normally computed by @TeX{}, so they are not under
1169 direct control of LilyPond. However, you can insert a commands into
1170 the @file{.tex} output to instruct @TeX{} where to break pages. This
1171 is done by setting the @code{between-systems-strings} on the
1172 @internalsref{NonMusicalPaperColumn} where the system is broken.
1173 An example is shown in @inputfileref{input/regression,between-systems.ly}.
1174 The predefined command @code{\newpage} also does this.
1178 @cindex @code{papersize}
1180 To change the paper size, use the following Scheme code:
1183 #(set-paper-size "a4")
1190 @cindex @code{\newpage}
1196 In this manual: @ref{Invoking lilypond}.
1198 Examples: @inputfileref{input/regression,between-systems.ly}.
1200 Internals: @internalsref{NonMusicalPaperColumn}.
1204 LilyPond has no concept of page layout, which makes it difficult to
1205 reliably choose page breaks in longer pieces.
1208 @node Interpretation context
1209 @section Interpretation context
1212 * Creating contexts::
1213 * Default contexts::
1214 * Context properties::
1215 * Defining contexts::
1216 * Changing contexts locally::
1217 * Engravers and performers::
1218 * Defining new contexts::
1222 Interpretation contexts are objects that only exist during program
1223 run. During the interpretation phase (when @code{interpreting music}
1224 is printed on the standard output), the music expression in a
1225 @code{\score} block is interpreted in time order, the same order in
1226 which we hear and play the music. During this phase, the interpretation
1227 context holds the state for the current point within the music, for
1230 @item What notes are playing at this point?
1232 @item What symbols will be printed at this point?
1234 @item What is the current key signature, time signature, point within
1238 Contexts are grouped hierarchically: A @internalsref{Voice} context is
1239 contained in a @internalsref{Staff} context (because a staff can contain
1240 multiple voices at any point), a @internalsref{Staff} context is contained in
1241 @internalsref{Score}, @internalsref{StaffGroup}, or
1242 @internalsref{ChoirStaff} context.
1244 Contexts associated with sheet music output are called @emph{notation
1245 contexts}, those for sound output are called @emph{performance
1246 contexts}. The default definitions of the standard notation and
1247 performance contexts can be found in @file{ly/engraver-init.ly} and
1248 @file{ly/performer-init.ly}, respectively.
1251 @node Creating contexts
1252 @subsection Creating contexts
1253 @cindex @code{\context}
1254 @cindex context selection
1256 Contexts for a music expression can be selected manually, using one of
1257 the following music expressions:
1260 \new @var{contexttype} @var{musicexpr}
1261 \context @var{contexttype} [= @var{contextname}] @var{musicexpr}
1265 This means that @var{musicexpr} should be interpreted within a context
1266 of type @var{contexttype} (with name @var{contextname} if specified).
1267 If no such context exists, it will be created:
1269 @lilypond[verbatim,raggedright]
1271 \notes \relative c'' {
1272 c4 <<d4 \context Staff = "another" e4>> f
1278 In this example, the @code{c} and @code{d} are printed on the default
1279 staff. For the @code{e}, a context @code{Staff} called @code{another}
1280 is specified; since that does not exist, a new context is created.
1281 Within @code{another}, a (default) Voice context is created for the
1282 @code{e4}. A context is ended when when all music referring it has
1283 finished, so after the third quarter, @code{another} is removed.
1285 The @code{\new} construction creates a context with a
1286 generated, unique @var{contextname}. An expression with
1287 @code{\new} always leads to a new context. This is convenient
1288 for creating multiple staves, multiple lyric lines, etc.
1290 When using automatic staff changes, automatic phrasing, etc., the
1291 context names have special meanings, so @code{\new} cannot be
1295 @node Default contexts
1296 @subsection Default contexts
1298 Every top level music is interpreted by the @code{Score} context; in
1299 other words, you may think of @code{\score} working like
1303 \context Score @var{music}
1307 Music expressions inherit their context from the enclosing music
1308 expression. Hence, it is not necessary to explicitly specify
1309 @code{\context} for most expressions. In
1310 the following example, only the sequential expression has an explicit
1311 context. The notes contained therein inherit the @code{goUp} context
1312 from the enclosing music expression.
1314 @lilypond[verbatim,raggedright]
1315 \notes \context Voice = goUp { c'4 d' e' }
1319 Second, contexts are created automatically to be able to interpret the
1320 music expressions. Consider the following example:
1322 @lilypond[verbatim,raggedright]
1323 \score { \notes { c'4-( d' e'-) } }
1327 The sequential music is interpreted by the Score context initially,
1328 but when a note is encountered, contexts are setup to accept that
1329 note. In this case, a @code{Voice}, and @code{Staff}
1330 context are created. The rest of the sequential music is also
1331 interpreted with the same @code{Voice}, and
1332 @code{Staff} context, putting the notes on the same staff, in the same
1335 @node Context properties
1336 @subsection Context properties
1338 Contexts have properties. These properties are set from the @file{.ly}
1339 file using the following expression:
1340 @cindex context properties
1341 @cindex properties, context
1344 \set @var{contextname}.@var{propname} = @var{value}
1348 Sets the @var{propname} property of the context @var{contextname} to
1349 the specified Scheme expression @var{value}. Both @var{propname} and
1350 @var{contextname} are strings, which can often be written unquoted.
1353 Properties that are set in one context are inherited by all of the
1354 contained contexts. This means that a property valid for the
1355 @internalsref{Voice} context can be set in the @internalsref{Score} context
1356 (for example) and thus take effect in all @internalsref{Voice} contexts.
1358 Properties can be unset using the following statement.
1360 \unset @var{contextname}.@var{propname}
1363 @cindex properties, unsetting
1364 @cindex @code{\unset}
1367 This removes the definition of @var{propname} in @var{contextname}. If
1368 @var{propname} was not defined in @var{contextname} (but was inherited
1369 from a higher context), then this has no effect.
1371 If @var{contextname} is left out, then it defaults to the current
1372 ``bottom'' context: this is a context like @internalsref{Voice} that
1373 cannot contain any other contexts.
1376 @node Defining contexts
1377 @subsection Defining contexts
1379 @cindex context definition
1380 @cindex translator definition
1382 The most common way to create a new context definition is by extending
1383 an existing one. An existing context from the paper block is copied
1384 by referencing a context identifier:
1389 @var{context-identifier}
1395 Every predefined context has a standard identifier. For example, the
1396 @code{Staff} context can be referred to as @code{\StaffContext}.
1398 The context can then be modified by setting or changing properties,
1403 Stem \set #'thickness = #2.0
1404 defaultBarType = #"||"
1407 These assignments happen before interpretation starts, so a property
1408 command will override any predefined settings.
1414 It is not possible to collect multiple property assignments in a
1415 variable, and apply to one @code{\context} definition by
1416 referencing that variable.
1418 @node Changing contexts locally
1419 @subsection Changing contexts locally
1422 Extending an existing context can also be done locally. A piece of
1423 music can be interpreted in a changed context by using the following syntax
1427 @var{context modifications}
1431 These statements comes between @code{\new} or @code{\context} and the
1432 music to be interpreted. The @var{context modifications} property
1433 settings and @code{\remove}, @code{\consists} and @code{\consistsend}
1434 commands. The syntax is similar to the @code{\context} block.
1436 The following example shows how a staff is created with bigger spaces,
1437 and without a @code{Clef_engraver}.
1439 @lilypond[relative=1,fragment,verbatim]
1441 \new Staff { c4 es4 g2 }
1443 \override StaffSymbol #'staff-space = #(magstep 1.5)
1445 \remove "Clef_engraver"
1453 The command @code{\with} has no effect on contexts that already
1457 @node Engravers and performers
1458 @subsection Engravers and performers
1461 Each context is composed of a number of building blocks, or plug-ins
1462 called engravers. An engraver is a specialized C++ class that is
1463 compiled into the executable. Typically, an engraver is responsible
1464 for one function: the @code{Slur_engraver} creates only @code{Slur}
1465 objects, and the @code{Skip_event_swallow_translator} only swallows
1466 (silently gobbles) @code{SkipEvent}s.
1473 An existing context definition can be changed by adding or removing an
1474 engraver. The syntax for these operations is
1476 \consists @var{engravername}
1477 \remove @var{engravername}
1480 @cindex @code{\consists}
1481 @cindex @code{\remove}
1484 Here @var{engravername} is a string, the name of an engraver in the
1485 system. In the following example, the @code{Clef_engraver} is removed
1486 from the Staff context. The result is a staff without a clef, where
1487 the middle C is at its default position, the center line:
1489 @lilypond[verbatim,raggedright]
1497 \remove Clef_engraver
1503 A list of all engravers is in the internal documentation,
1504 see @internalsref{Engravers}.
1506 @node Defining new contexts
1507 @subsection Defining new contexts
1510 It is also possible to define new contexts from scratch. To do this,
1511 you must define give the new context a name. In the following
1512 example, a very simple Staff context is created: one that will put
1513 note heads on a staff symbol.
1517 \type "Engraver_group_engraver"
1520 \consists "Staff_symbol_engraver"
1521 \consists "Note_head_engraver"
1522 \consistsend "Axis_group_engraver"
1527 The argument of @code{\type} is the name for a special engraver that
1528 handles cooperation between simple engravers such as
1529 @code{Note_head_engraver} and @code{Staff_symbol_engraver}. This
1530 should always be @code{Engraver_group_engraver} (unless you are
1531 defining a Score context from scratch, in which case
1532 @code{Score_engraver} must be used).
1534 The complete list of context modifiers is the following:
1536 @item @code{\alias} @var{alternate-name}:
1537 This specifies a different name. In the above example,
1538 @code{\set Staff.X = Y} will also work on @code{SimpleStaff}s.
1540 @item @code{\consistsend} @var{engravername}:
1541 Analogous to @code{\consists}, but makes sure that
1542 @var{engravername} is always added to the end of the list of
1545 Engravers that group context objects into axis groups or alignments
1546 need to be at the end of the list. @code{\consistsend} insures that
1547 engravers stay at the end even if a user adds or removes engravers.
1549 @item @code{\accepts} @var{contextname}:
1550 This context can contains @var{contextname} contexts. The first
1551 @code{\accepts} is created as a default context when events (e.g. notes
1552 or rests) are encountered.
1554 @item @code{\denies}:
1555 The opposite of @code{\accepts}.
1557 @item @code{\name} @var{contextname}:
1558 This sets the type name of the context, e.g. @code{Staff},
1559 @code{Voice}. If the name is not specified, the translator will not
1568 @node Output details
1569 @section Output details
1571 The default output format is La@TeX{}, which should be run
1572 through La@TeX{}. Using the option @option{-f}
1573 (or @option{--format}) other output formats can be selected also, but
1574 none of them work reliably.
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.