2 @node Changing defaults
3 @chapter Changing defaults
6 The purpose of LilyPond's design is to provide the finest output
7 quality as a default. Nevertheless, it may happen that you need to
8 change that default layout. The layout is controlled through a large
9 number of proverbial ``knobs and switches.'' This chapter does not
10 list each and every knob. Rather, it outlines what groups of controls
11 are available, and how to tune them.
13 Which controls are available for tuning is described in a separate
14 document, the @internalsref{Program reference} manual. This manual
15 lists all different variables, functions and options available in
16 LilyPond. It is available as a HTML document, which is available
17 @uref{http://lilypond.org/doc/Documentation/user/out-www/lilypond-internals/,on-line},
18 but is also included with the LilyPond documentation package.
20 There are X areas where the default settings may be changed:
23 @item Output: changing the appearance of individual
25 @item Context: changing the translation from music events to
27 @item Global layout: changing the appearance of the spacing, line
28 breaks and page dimensions.
31 Then, there are separate systems for typesetting text (like
32 @emph{ritardando}) and selecting different fonts. This chapter also
35 Internally, LilyPond uses Scheme (a LISP dialect) to provide
36 infrastructure. Since overriding layout decisions in effect
37 accesses the program internals, it is necessary to learn a (very
38 small) subset of Scheme. That is why this chapter starts with
39 a short tutorial on entering numbers, lists, strings and symbols in
46 * Fine tuning layout::
50 * Interpretation context::
55 @section Scheme tutorial
59 @cindex Scheme, in-line code
60 @cindex accessing Scheme
61 @cindex evaluating Scheme
64 LilyPond uses the Scheme programming language, both as part of the
65 input syntax, and as internal mechanism to glue together modules of
66 the program. This section is a very brief overview of entering data in
67 Scheme.@footnote{If you want to know more about Scheme, see
68 @uref{http://www.schemers.org}.}
70 The most basic thing of a language is data: numbers, character
71 strings, lists, etc. Here is a list of data types that are relevant to
76 Boolean values are True or False. The Scheme for True is @code{#t}
77 and False is @code{#f}.
79 Numbers are entered in the standard fashion,
80 @code{1} is the (integer) number one, while @code{-1.5} is a
81 floating point number (a non-integer number).
83 Strings are enclosed in double quotes,
88 Strings may span several lines
95 Quotation marks and newlines can also be added with so-called escape
96 sequences. The string @code{a said "b"} is entered as
101 Newlines and backslashes are escaped with @code{\n} and @code{\\}
106 In a music file, snippets of Scheme code are introduced with the hash
107 mark @code{#}. So, the previous examples translated in LilyPondese are
118 For the rest of this section, we will assume that the data is entered
119 in a music file, so we add @code{#}s everywhere.
121 Scheme can be used to do calculations. It uses @emph{prefix}
122 syntax. Adding 1 and 2 is written as @code{(+ 1 2)} rather than the
130 The arrow @result{} shows that the result of evaluating @code{(+ 1 2)}
131 is @code{3}. Calculations may be nested: the result of a function may
132 be used for another calculation.
140 These calculations are examples of evaluations: an expression (like
141 @code{(* 3 4)} is replaced by its value @code{12}. A similar thing
142 happens with variables. After defining a variable
148 variables can also be used in expressions, here
151 twentyFour = #(* 2 twelve)
154 the number 24 is stored in the variable @code{twentyFour}.
156 The @emph{name} of a variable is also an expression, similar to a
157 number or a string. It is entered as
163 The quote mark @code{'} prevents Scheme interpreter from substituting
164 @code{24} for the @code{twentyFour}. Instead, we get the name
167 This syntax will be used very frequently, since many of the layout
168 tweaks involve assigning (Scheme) values to variables, for example
171 \override Stem #'thickness = #2.5
174 This instruction adjusts the appearance of stems. The value @code{2.5}
175 is put into a the @code{thickness} variable of a @code{Stem}
176 object. This makes stems almost twice as thick as their normal size.
178 Two-dimensional offsets (X and Y coordinates) as well as object sizes
179 (intervals with a left and right point) are entered as @code{pairs}. A
180 pair@footnote{In Scheme terminology, the pair is called @code{cons},
181 and its two elements are called car and cdr respectively.} is entered
182 as @code{(first . second)}, and like symbols, they must be quoted,
185 \override TextScript #'extra-offset = #'(1 . 2)
188 This assigns the pair (1, 2) to @code{extra-offset} variable of the
189 TextScript object. This moves the object 1 staff space to the right,
192 The two elements of a pair may be arbitrary values, for example
197 #'("blah-blah" . 3.14159265)
200 A list is entered by enclosing its elements in parentheses, and
201 adding a quote. . For example,
207 We have been using lists all along. A calculation, like @code{(+ 1
208 2)} is also a list (containing the symbol @code{+} and the numbers 1
209 and 2). For entering lists, use a quote @code{'} and for
210 calculations, do not use a quote.
212 Inside a quoted list or pair, there is no need to quote anymore. The
213 following is a pair and a list of symbols respectively.
216 #'(staff clef key-signature)
225 @subsection Inline Scheme
227 Scheme expressions can be entered in the input file by entering a
228 hash-sign (@code{#}). The expression following the hash-sign is
229 evaluated as Scheme. For example, the boolean value @var{true} is
230 @code{#t} in Scheme, so for LilyPond @var{true} looks like @code{##t},
231 and can be used in property assignments:
233 \set Staff.autoBeaming = ##f
237 @node Setting variables
238 @section Setting variables
240 When the music is converted from notes to print it is interpreted
241 in left-to-right order. This is similar to what happens when we read
242 music. During this step context-sensitive information such as the
243 accidentals to print, and where bar lines must be placed, are stored in
244 variables. These variables are called @emph{context properties}.
245 The properties can also be manipulated from input files. Consider this input:
247 \set Staff.autoBeaming = ##f
251 It sets the property named @code{autoBeaming} in the current staff at
252 this point in the music to @code{##f}, which means `false'. This
253 property controls whether beams are printed automatically:
255 @lilypond[relative=1,fragment,verbatim]
257 \set Staff.autoBeaming = ##f
262 LilyPond includes a built-in programming language, namely, a dialect
263 of Scheme. The argument to @code{\set}, @code{##f}, is an
264 expression in that language. The first hash-mark signals that a piece
265 of Scheme code follows. The second hash character is part of the
266 boolean value true (@code{#t}). Values of other types may be
269 @item a string, enclosed in double quotes, for example,
271 \set Staff.instrument = #"French Horn"
273 @item a boolean: either @code{#t} or @code{#f}, for true and false
276 \set autoBeaming = ##f
277 \set Score.skipBars = ##t
280 @item a number, such as
282 \set Score.currentBarNumber = #20
285 @item a symbol, which is introduced by a quote character, as in
287 \set Staff.crescendoSpanner = #'dashed-line
290 @item a pair, which is also introduced by a quote character, like in
291 the following statements, which set properties to the pairs (-7.5, 6)
292 and (3, 4) respectively:
295 \set Staff.minimumVerticalExtent = #'(-7.5 . 6)
296 \set Staff.timeSignatureFraction = #'(3 . 4)
299 @item a list, which is also introduced by a quote character. In the
300 following example, the @code{breakAlignOrder} property is set to a
303 \set Score.breakAlignOrder =
304 #'(left-edge time-signature key-signatures)
310 There are many different properties. Not all of them are listed in
311 this manual. However, the program reference lists them all in the
312 section @internalsref{Context-properties}, and most properties are
313 demonstrated in one of the
315 @uref{../../../input/test/out-www/collated-files.html,tips-and-tricks}
323 @node Fine tuning layout
324 @section Fine tuning layout
326 Sometimes it is necessary to change music layout by hand. When music
327 is formatted, layout objects are created for each symbol. For
328 example, every clef and every note head is represented by a layout
329 object. These layout objects also carry variables, which we call
330 @emph{layout properties}. By changing these variables from their
331 values, we can alter the look of a formatted score:
333 @lilypond[verbatim,relative]
335 \override Stem #'thickness = #3.0
340 In the example shown here, the layout property @code{thickness} (a
341 symbol) is set to 3 in the @code{Stem} layout objects of the current
342 As a result, the notes following @code{\override} have thicker
345 For the most part, a manual override is needed only on a case by
346 case basis and not for all subsequent instances of the altered
347 property. To accomplish this, simply prefix @code{\once} to the
348 @code{\override} statement and the override will apply only once,
349 immediately reverting to its default setting, i.e.
352 \once \override Stem #'thickness = #3.0
357 \once \override Stem #'thickness = #3.0
362 Some overrides are so common that predefined commands are provided as
363 a short cut. For example, @code{\slurUp} and @code{\stemDown}. These
364 commands are described in
368 @ref{Notation manual}, under the sections for slurs and stems
371 The exact tuning possibilities for each type of layout object are
372 documented in the program reference of the respective
373 object. However, many layout objects share properties, which can be
374 used to apply generic tweaks. We mention a couple of these:
377 @item The @code{extra-offset} property, which
378 @cindex @code{extra-offset}
379 has a pair of numbers as value, moves around objects in the printout.
380 The first number controls left-right movement; a positive number will
381 move the object to the right. The second number controls up-down
382 movement; a positive number will move it higher. The units of these
383 offsets are staff-spaces. The @code{extra-offset} property is a
384 low-level feature: the formatting engine is completely oblivious to
387 In the following example, the second fingering is moved a little to
388 the left, and 1.8 staff space downwards:
390 @cindex setting object properties
392 @lilypond[relative=1,verbatim]
395 \once \override Fingering
396 #'extra-offset = #'(-0.3 . -1.8)
401 Setting the @code{transparent} property will cause an object to be printed
402 in `invisible ink': the object is not printed, but all its other
403 behavior is retained. The object still takes up space, it takes part in
404 collisions, and slurs, and ties and beams can be attached to it.
406 @cindex transparent objects
407 @cindex removing objects
408 @cindex invisible objects
409 The following example demonstrates how to connect different voices
410 using ties. Normally, ties only connect two notes in the same
411 voice. By introducing a tie in a different voice, and blanking a stem
412 in that voice, the tie appears to cross voices:
414 @lilypond[fragment,relative=1,verbatim]
416 \once \override Stem #'transparent = ##t
424 The @code{padding} property for objects with
425 @cindex @code{padding}
426 @code{side-position-interface} can be set to increase distance between
427 symbols that are printed above or below notes. We only give an
428 example; a more elaborate explanation is in @ref{Constructing a
431 @lilypond[relative=1,verbatim]
433 \override Script #'padding = #3
439 More specific overrides are also possible. The notation manual
440 discusses in depth how to figure out these statements for yourself, in
447 @section Tuning output
449 There are situations where default layout decisions are not
450 sufficient. In this section we discuss ways to override these
453 Formatting is internally done by manipulating so called objects
454 (graphic objects). Each object carries with it a set of properties
455 (object or layout properties) specific to that object. For example, a
456 stem object has properties that specify its direction, length and
459 The most direct way of tuning the output is by altering the values of
460 these properties. There are two ways of doing that: first, you can
461 temporarily change the definition of one type of object, thus
462 affecting a whole set of objects. Second, you can select one specific
463 object, and set a layout property in that object.
465 Do not confuse layout properties with translation
466 properties. Translation properties always use a mixed caps style
467 naming, and are manipulated using @code{\set} and @code{\unset}:
469 \set Context.propertyName = @var{value}
472 Layout properties are use Scheme style variable naming, i.e. lower
473 case words separated with dashes. They are symbols, and should always
474 be quoted using @code{#'}. For example, this could be an imaginary
475 layout property name:
477 #'layout-property-name
483 * Constructing a tweak::
484 * Selecting font sizes::
491 @subsection Tuning objects
493 @cindex object description
495 The definition of an object is a list of default object
496 properties. For example, the definition of the Stem object (available
497 in @file{scm/define-grobs.scm}), includes the following definitions
498 for @internalsref{Stem}:
502 (beamed-lengths . (3.5 3.5 3.5 4.5 5.0))
503 (Y-extent-callback . ,Stem::height)
508 Adding variables on top of this existing definition overrides the
509 system default, and alters the resulting appearance of the layout
515 Changing a variable for only one object is commonly achieved with
519 \once \override @var{context}.@var{objectname}
520 @var{symbol} = @var{value}
522 Here @var{symbol} is a Scheme expression of symbol type, @var{context}
523 and @var{objectname} is a string and @var{value} is a Scheme expression.
524 This command applies a setting only during one moment in the score.
526 In the following example, only one @internalsref{Stem} object is
527 changed from its original setting:
529 @lilypond[verbatim,fragment,relative=1]
531 \once \override Voice.Stem #'thickness = #4
537 For changing more objects, the same command, without @code{\once} can
540 \override @var{context}.@var{objectname} @var{symbol} = @var{value}
542 This command adds @code{@var{symbol} = @var{value}} to the definition
543 of @var{objectname} in the context @var{context}, and this definition
544 stays in place until it is removed.
546 An existing definition may be removed by the following command:
549 \property @var{context}.@var{objectname} \revert @var{symbol}
555 c'4 \override Stem #'thickness = #4.0
557 c'4 \revert Stem #'thickness
563 Reverting a setting which was not set in the first place has no
569 Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
570 @internalsref{PropertySet}, @internalsref{All-backend-properties}, and
571 @internalsref{All-layout-objects}.
576 The back-end is not very strict in type-checking object properties.
577 Cyclic references in Scheme values for properties can cause hangs
581 @node Constructing a tweak
582 @subsection Constructing a tweak
585 @cindex internal documentation
586 @cindex finding graphical objects
587 @cindex graphical object descriptions
589 @cindex @code{\override}
591 @cindex internal documentation
595 Three pieces of information are required to use @code{\override} and
596 @code{\set}: the name of the layout object, the context and the name
597 of the property. We demonstrate how to glean this information from
598 the notation manual and the program reference.
600 The generated documentation is a set of HTML pages which should be
601 included if you installed a binary distribution, typically in
602 @file{/usr/share/doc/lilypond}. They are also available on the web:
603 go to the @uref{http://lilypond.org,LilyPond website}, click
604 ``Documentation'', select the correct version, and then click
605 ``Program reference.'' It is advisable to bookmark the local HTML
606 files. They will load faster than the ones on the web and matches the
607 version of LilyPond you are using.
611 @c [TODO: revise for new site.]
613 Suppose we want to move the fingering indication in the fragment
616 @lilypond[relative=2,verbatim]
622 If you visit the documentation of @code{Fingering} (in @ref{Fingering
623 instructions}), you will notice that there is written:
628 Internals: @internalsref{FingerEvent} and @internalsref{Fingering}.
635 In other words, the fingerings once entered, are internally stored as
636 @code{FingerEvent} music objects. When printed, a @code{Fingering}
637 layout object is created for every @code{FingerEvent}.
639 The Fingering object has a number of different functions, and each of
640 those is captured in an interface. The interfaces are listed under
641 @internalsref{Fingering} in the program reference.
645 The @code{Fingering} object has a fixed size
646 (@internalsref{item-interface}), the symbol is a piece of text
647 (@internalsref{text-interface}), whose font can be set
648 (@internalsref{font-interface}). It is centered horizontally
649 (@internalsref{self-alignment-interface}), it is placed vertically
650 next to other objects (@internalsref{side-position-interface}), and
651 its placement is coordinated with other scripts
652 (@internalsref{text-script-interface}). It also has the standard
653 @internalsref{grob-interface} (grob stands for Graphical object)
655 @cindex graphical object
656 @cindex layout object
657 @cindex object, layout
658 with all the variables that come with
659 it. Finally, it denotes a fingering instruction, so it has
660 @internalsref{finger-interface}.
662 For the vertical placement, we have to look under
663 @code{side-position-interface}:
665 @code{side-position-interface}
667 Position a victim object (this one) next to other objects (the
668 support). In this case, the property @code{direction} signifies where to put the
669 victim object relative to the support (left or right, up or down?)
674 below this description, the variable @code{padding} is described as
678 (dimension, in staff space)
680 add this much extra space between objects that are next to each
681 other. Default value: @code{0.6}
685 By increasing the value of @code{padding}, we can move away the
686 fingering. The following command inserts 3 staff spaces of white
687 between the note and the fingering:
689 \once \override Fingering #'padding = #3
692 Inserting this command before the Fingering object is created,
693 i.e. before @code{c2}, yields the following result:
695 @lilypond[relative=2,fragment,verbatim]
696 \once \override Fingering
703 The context name @code{Voice} in the example above can be determined
704 as follows. In the documentation for @internalsref{Fingering}, it says
706 Fingering grobs are created by: @internalsref{Fingering_engraver} @c
709 Clicking @code{Fingering_engraver} shows the documentation of
710 the module responsible for interpreting the fingering instructions and
711 translating them to a @code{Fingering} object. Such a module is called
712 an @emph{engraver}. The documentation of the @code{Fingering_engraver}
715 Fingering_engraver is part of contexts: Voice
717 so tuning the settings for Fingering should be done with
719 \override Fingering @dots{}
722 Of course, the tweak may also done in a larger context than
723 @code{Voice}, for example, @internalsref{Staff} or
724 @internalsref{Score}.
728 Internals: the program reference also contains alphabetical lists of
729 @internalsref{Contexts}, @internalsref{All-layout-objects} and
730 @internalsref{Music-expressions}, so you can also find which objects
731 to tweak by browsing the internals document.
734 @node Selecting font sizes
735 @subsection Selecting font sizes
737 The most common thing to change about the appearance of fonts is their
738 size. The font size of any context can be easily changed by setting
739 the @code{fontSize} property for that context. Its value is a number:
740 negative numbers make the font smaller, positive numbers larger. An
741 example is given below:
743 @lilypond[fragment,relative=1,verbatim]
744 c4 c4 \set fontSize = #-3
747 This command will set @code{font-size} (see below) in all layout
748 objects in the current context. It does not change the size of
749 variable symbols, such as beams or slurs.
751 The font size is set by modifying the @code{font-size} property. Its
752 value is a number indicating the size relative to the standard size.
753 Each step up is an increase of approximately 12% of the font size. Six
754 steps is exactly a factor two. The Scheme function @code{magstep}
755 converts a @code{font-size} number to a scaling factor.
757 LilyPond has fonts in different design sizes: the music fonts for
758 smaller sizes are chubbier, while the text fonts are relatively wider.
759 Font size changes are achieved by scaling the design size that is
760 closest to the desired size.
762 The @code{font-size} mechanism does not work for fonts selected
763 through @code{font-name}. These may be scaled with
764 @code{font-magnification}.
767 One of the uses of @code{fontSize} is to get smaller symbols for cue
768 notes. An elaborate example of those is in
769 @inputfileref{input/test,cue-notes.ly}.
771 @cindex @code{font-style}
775 The following commands set @code{fontSize} for the current voice.
779 @cindex @code{\small}
781 @cindex @code{\normalsize}
786 @cindex magnification
791 @subsection Font selection
793 Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
794 can also be adjusted with a more fine-grained mechanism. By setting
795 the object properties described below, you can select a different font;
796 all three mechanisms work for every object that supports
797 @code{font-interface}:
801 @item @code{font-encoding}
802 is a symbol that sets layout of the glyphs. Choices include
803 @code{text} for normal text, @code{braces} (for piano staff braces),
804 @code{music} (the standard music font, including ancient glyphs),
805 @code{dynamic} (for dynamic signs) and @code{number} for the number
809 @item @code{font-family}
810 is a symbol indicating the general class of the typeface. Supported are
811 @code{roman} (Computer Modern), @code{sans} and @code{typewriter}
813 @item @code{font-shape}
814 is a symbol indicating the shape of the font, there are typically
815 several font shapes available for each font family. Choices are
816 @code{italic}, @code{caps} and @code{upright}.
818 @item @code{font-series}
819 is a symbol indicating the series of the font. There are typically several
820 font series for each font family and shape. Choices are @code{medium}
825 Fonts selected in the way sketched above come from a predefined style
828 The font used for printing a object can be selected by setting
829 @code{font-name}, e.g.
831 \override Staff.TimeSignature
832 #'font-name = #"cmr17"
836 Any font can be used, as long as it is available to @TeX{}. Possible
837 fonts include foreign fonts or fonts that do not belong to the
838 Computer Modern font family. The size of fonts selected in this way
839 can be changed with the @code{font-magnification} property. For
840 example, @code{2.0} blows up all letters by a factor 2 in both
844 @cindex font magnification
850 Init files: @file{ly/declarations-init.ly} contains hints how new
851 fonts may be added to LilyPond.
855 No style sheet is provided for other fonts besides the @TeX{}
856 Computer Modern family.
858 @cindex font selection
859 @cindex font magnification
860 @cindex @code{font-interface}
871 LilyPond has an internal mechanism to typeset texts. You can access it
872 with the keyword @code{\markup}. Within markup mode, you can enter texts
873 similar to lyrics: simply enter them, surrounded by spaces:
876 @lilypond[verbatim,fragment,relative=1]
878 c1_\markup { hi there }
879 c1^\markup { hi \bold there, is \italic anyone home? }
882 @cindex font switching
884 The markup in the example demonstrates font switching commands. The
885 command @code{\bold} and @code{\italic} only apply to the first
886 following word; enclose a set of texts with braces to apply a command
889 \markup @{ \bold @{ hi there @} @}
893 For clarity, you can also do this for single arguments, e.g.
896 \markup { is \italic { anyone } home }
899 @cindex font size, texts
902 In markup mode you can compose expressions, similar to mathematical
903 expressions, XML documents and music expressions. The braces group
904 notes into horizontal lines. Other types of lists also exist: you can
905 stack expressions grouped with @code{<}, and @code{>} vertically with
906 the command @code{\column}. Similarly, @code{\center-align} aligns
907 texts by their center lines:
909 @lilypond[verbatim,fragment,relative=1]
910 c1^\markup { \column < a bbbb c > }
911 c1^\markup { \center-align < a bbbb c > }
912 c1^\markup { \line < a b c > }
916 Markups can be stored in variables, and these variables
917 may be attached to notes, like
919 allegro = \markup { \bold \large { Allegro } }
920 \notes { a^\allegro b c d }
924 Some objects have alignment procedures of their own, which cancel out
925 any effects of alignments applied to their markup arguments as a
926 whole. For example, the @internalsref{RehearsalMark} is horizontally
927 centered, so using @code{\mark \markup @{ \left-align .. @}} has no
930 Similarly, for moving whole texts over notes with
931 @code{\raise}, use the following trick:
933 "" \raise #0.5 raised
936 The text @code{raised} is now raised relative to the empty string
937 @code{""} which is not visible. Alternatively, complete objects can
938 be moved with layout properties such as @code{padding} and
945 Init files: @file{scm/new-markup.scm}.
950 Text layout is ultimately done by @TeX{}, which does kerning of
951 letters. LilyPond does not account for kerning, so texts will be
952 spaced slightly too wide.
954 Syntax errors for markup mode are confusing.
956 Markup texts cannot be used in the titling of the @code{\header}
957 field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
963 * Overview of text markup commands::
966 @node Overview of text markup commands
967 @subsection Overview of text markup commands
969 @include markup-commands.tely
973 @section Global layout
975 The global layout determined by three factors: the page layout, the
976 line breaks and the spacing. These all influence each other. The
977 choice of spacing determines how densely each system of music is set,
978 which influences where line breaks breaks are chosen, and thus
979 ultimately how many pages a piece of music takes. This section
980 explains how to tune the algorithm for spacing.
982 Globally spoken, this procedure happens in three steps: first,
983 flexible distances (``springs'') are chosen, based on durations. All
984 possible line breaking combination are tried, and the one with the
985 best results---a layout that has uniform density and requires as
986 little stretching or cramping as possible---is chosen. When the score
987 is processed by @TeX{}, each page is filled with systems, and page breaks
988 are chosen whenever the page gets full.
994 * Horizontal spacing::
1001 @node Vertical spacing
1002 @subsection Vertical spacing
1004 @cindex vertical spacing
1005 @cindex distance between staves
1006 @cindex staff distance
1007 @cindex between staves, distance
1008 @cindex staves per page
1009 @cindex space between staves
1011 The height of each system is determined automatically by LilyPond, to
1012 keep systems from bumping into each other, some minimum distances are
1013 set. By changing these, you can put staves closer together, and thus
1014 put more systems onto one page.
1016 Normally staves are stacked vertically. To make
1017 staves maintain a distance, their vertical size is padded. This is
1018 done with the property @code{minimumVerticalExtent}. It takes a pair
1019 of numbers, so if you want to make it smaller from its, then you could
1022 \set Staff.minimumVerticalExtent = #'(-4 . 4)
1024 This sets the vertical size of the current staff to 4 staff spaces on
1025 either side of the center staff line. The argument of
1026 @code{minimumVerticalExtent} is interpreted as an interval, where the
1027 center line is the 0, so the first number is generally negative. The
1028 staff can be made larger at the bottom by setting it to @code{(-6
1031 The piano staves are handled a little differently: to make cross-staff
1032 beaming work correctly, it is necessary that the distance between staves
1033 is fixed beforehand. This is also done with a
1034 @internalsref{VerticalAlignment} object, created in
1035 @internalsref{PianoStaff}. In this object the distance between the
1036 staves is fixed by setting @code{forced-distance}. If you want to
1037 override this, use a @code{\context} block as follows:
1042 \override VerticalAlignment #'forced-distance = #9
1047 This would bring the staves together at a distance of 9 staff spaces,
1048 measured from the center line of each staff.
1052 Internals: Vertical alignment of staves is handled by the
1053 @internalsref{VerticalAlignment} object.
1058 @node Horizontal spacing
1059 @subsection Horizontal Spacing
1061 The spacing engine translates differences in durations into
1062 stretchable distances (``springs'') of differing lengths. Longer
1063 durations get more space, shorter durations get less. The shortest
1064 durations get a fixed amount of space (which is controlled by
1065 @code{shortest-duration-space} in the @internalsref{SpacingSpanner} object).
1066 The longer the duration, the more space it gets: doubling a
1067 duration adds a fixed amount (this amount is controlled by
1068 @code{spacing-increment}) of space to the note.
1070 For example, the following piece contains lots of half, quarter and
1071 8th notes, the eighth note is followed by 1 note head width (NHW).
1072 The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
1073 @lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8
1077 Normally, @code{shortest-duration-space} is set to 1.2, which is the
1078 width of a note head, and @code{shortest-duration-space} is set to
1079 2.0, meaning that the shortest note gets 2 NHW (i.e. 2 times
1080 @code{shortest-duration-space}) of space. For normal notes, this space
1081 is always counted from the left edge of the symbol, so the shortest
1082 notes are generally followed by one NHW of space.
1084 If one would follow the above procedure exactly, then adding a single
1085 32th note to a score that uses 8th and 16th notes, would widen up the
1086 entire score a lot. The shortest note is no longer a 16th, but a 32nd,
1087 thus adding 1 NHW to every note. To prevent this, the
1088 shortest duration for spacing is not the shortest note in the score,
1089 but the most commonly found shortest note. Notes that are even
1090 shorter this are followed by a space that is proportional to their
1091 duration relative to the common shortest note. So if we were to add
1092 only a few 16th notes to the example above, they would be followed by
1095 @lilypond[fragment,verbatim,relative=2]
1096 c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4
1099 The most common shortest duration is determined as follows: in every
1100 measure, the shortest duration is determined. The most common short
1101 duration, is taken as the basis for the spacing, with the stipulation
1102 that this shortest duration should always be equal to or shorter than
1103 1/8th note. The shortest duration is printed when you run lilypond
1104 with @code{--verbose}. These durations may also be customized. If you
1105 set the @code{common-shortest-duration} in
1106 @internalsref{SpacingSpanner}, then this sets the base duration for
1107 spacing. The maximum duration for this base (normally 1/8th), is set
1108 through @code{base-shortest-duration}.
1110 @cindex @code{common-shortest-duration}
1111 @cindex @code{base-shortest-duration}
1112 @cindex @code{stem-spacing-correction}
1113 @cindex @code{spacing}
1115 In the introduction it was explained that stem directions influence
1116 spacing. This is controlled with @code{stem-spacing-correction}
1117 property in @internalsref{NoteSpacing}, which are generated for every
1118 @internalsref{Voice} context. The @code{StaffSpacing} object
1119 (generated at @internalsref{Staff} context) contains the same property
1120 for controlling the stem/bar line spacing. The following example
1121 shows these corrections, once with default settings, and once with
1122 exaggerated corrections:
1128 \override Staff.NoteSpacing #'stem-spacing-correction
1130 \override Staff.StaffSpacing #'stem-spacing-correction
1135 \paper { raggedright = ##t } }
1138 @cindex SpacingSpanner, overriding properties
1140 Properties of the @internalsref{SpacingSpanner} must be overridden
1141 from the @code{\paper} block, since the @internalsref{SpacingSpanner} is
1142 created before any property commands are interpreted.
1144 \paper @{ \context @{
1146 SpacingSpanner \override #'spacing-increment = #3.0
1153 Internals: @internalsref{SpacingSpanner}, @internalsref{NoteSpacing},
1154 @internalsref{StaffSpacing}, @internalsref{SeparationItem}, and
1155 @internalsref{SeparatingGroupSpanner}.
1159 Spacing is determined on a score wide basis. If you have a score that
1160 changes its character (measured in durations) halfway during the
1161 score, the part containing the longer durations will be spaced too
1164 There is no convenient mechanism to manually override spacing.
1169 @subsection Font size
1171 @cindex font size, setting
1172 @cindex staff size, setting
1173 @cindex @code{paper} file
1175 The Feta font provides musical symbols at eight different
1176 sizes. Each font is tuned for a different staff size: at smaller sizes
1177 the font gets heavier, to match the relatively heavier staff lines.
1178 The recommended font sizes are listed in the following table:
1180 @multitable @columnfractions .25 .25 .25 .25
1183 @tab @b{staff height (pt)}
1184 @tab @b{staff height (mm)}
1226 @c modern rental material ?
1230 These fonts are available in any sizes. The context property
1231 @code{fontSize} and the layout property @code{staff-space} (in
1232 @internalsref{StaffSymbol}) can be used to tune size for individual
1233 staves. The size of individual staves are relative to the global size,
1234 which can be set in the following manner:
1237 #(set-global-staff-size 14)
1240 This sets the global default size to 14pt staff height, and scales all
1245 This manual: @ref{Selecting font sizes}.
1249 @subsection Line breaking
1252 @cindex breaking lines
1254 Line breaks are normally computed automatically. They are chosen such
1255 that lines look neither cramped nor loose, and that consecutive lines
1256 have similar density.
1258 Occasionally you might want to override the automatic breaks; you can
1259 do this by specifying @code{\break}. This will force a line break at
1260 this point. Line breaks can only occur at places where there are bar
1261 lines. If you want to have a line break where there is no bar line,
1262 you can force an invisible bar line by entering @code{\bar
1263 ""}. Similarly, @code{\noBreak} forbids a line break at a
1267 @cindex regular line breaks
1268 @cindex four bar music.
1270 For line breaks at regular intervals use @code{\break} separated by
1271 skips and repeated with @code{\repeat}:
1273 << \repeat unfold 7 @{
1274 s1 \noBreak s1 \noBreak
1275 s1 \noBreak s1 \break @}
1276 @emph{the real music}
1281 This makes the following 28 measures (assuming 4/4 time) be broken every
1282 4 measures, and only there.
1286 @code{\break}, @code{\noBreak}
1287 @cindex @code{\break}
1288 @cindex @code{\noBreak}
1292 Internals: @internalsref{BreakEvent}.
1296 @subsection Page layout
1299 @cindex breaking pages
1301 @cindex @code{indent}
1302 @cindex @code{linewidth}
1304 The most basic settings influencing the spacing are @code{indent} and
1305 @code{linewidth}. They are set in the @code{\paper} block. They
1306 control the indentation of the first line of music, and the lengths of
1309 If @code{raggedright} is set to true in the @code{\paper}
1310 block, then the lines are justified at their natural length. This
1311 useful for short fragments, and for checking how tight the natural
1315 @cindex vertical spacing
1317 The page layout process happens outside the LilyPond formatting
1318 engine: variables controlling page layout are passed to the output,
1319 and are further interpreted by @code{lilypond} wrapper program. It
1320 responds to the following variables in the @code{\paper} block. The
1321 spacing between systems is controlled with @code{interscoreline}, its
1322 default is 16pt. The distance between the score lines will stretch in
1323 order to fill the full page @code{interscorelinefill} is set to a
1324 positive number. In that case @code{interscoreline} specifies the
1327 @cindex @code{textheight}
1328 @cindex @code{interscoreline}
1329 @cindex @code{interscorelinefill}
1331 If the variable @code{lastpagefill} is defined,
1332 @c fixme: this should only be done if lastpagefill= #t
1333 systems are evenly distributed vertically on the last page. This
1334 might produce ugly results in case there are not enough systems on the
1335 last page. The @command{lilypond-book} command ignores
1336 @code{lastpagefill}. See @ref{lilypond-book manual} for more
1339 @cindex @code{lastpagefill}
1341 Page breaks are normally computed by @TeX{}, so they are not under
1342 direct control of LilyPond. However, you can insert a commands into
1343 the @file{.tex} output to instruct @TeX{} where to break pages. This
1344 is done by setting the @code{between-systems-strings} on the
1345 @internalsref{NonMusicalPaperColumn} where the system is broken.
1346 An example is shown in @inputfileref{input/regression,between-systems.ly}.
1347 The predefined command @code{\newpage} also does this.
1351 @cindex @code{papersize}
1353 To change the paper size, use the following Scheme code:
1356 #(set-paper-size "a4")
1363 @cindex @code{\newpage}
1369 In this manual: @ref{Invoking lilypond}.
1371 Examples: @inputfileref{input/regression,between-systems.ly}.
1373 Internals: @internalsref{NonMusicalPaperColumn}.
1377 LilyPond has no concept of page layout, which makes it difficult to
1378 reliably choose page breaks in longer pieces.
1381 @node Interpretation context
1382 @section Interpretation context
1385 * Creating contexts::
1386 * Default contexts::
1387 * Context properties::
1388 * Defining contexts::
1389 * Changing contexts locally::
1390 * Engravers and performers::
1391 * Defining new contexts::
1395 Interpretation contexts are objects that only exist during program
1396 run. During the interpretation phase (when @code{interpreting music}
1397 is printed on the standard output), the music expression in a
1398 @code{\score} block is interpreted in time order, the same order in
1399 which we hear and play the music. During this phase, the interpretation
1400 context holds the state for the current point within the music, for
1403 @item What notes are playing at this point?
1405 @item What symbols will be printed at this point?
1407 @item What is the current key signature, time signature, point within
1411 Contexts are grouped hierarchically: A @internalsref{Voice} context is
1412 contained in a @internalsref{Staff} context (because a staff can contain
1413 multiple voices at any point), a @internalsref{Staff} context is contained in
1414 @internalsref{Score}, @internalsref{StaffGroup}, or
1415 @internalsref{ChoirStaff} context.
1417 Contexts associated with sheet music output are called @emph{notation
1418 contexts}, those for sound output are called @emph{performance
1419 contexts}. The default definitions of the standard notation and
1420 performance contexts can be found in @file{ly/engraver-init.ly} and
1421 @file{ly/performer-init.ly}, respectively.
1424 @node Creating contexts
1425 @subsection Creating contexts
1426 @cindex @code{\context}
1427 @cindex context selection
1429 Contexts for a music expression can be selected manually, using one of
1430 the following music expressions:
1433 \new @var{contexttype} @var{musicexpr}
1434 \context @var{contexttype} [= @var{contextname}] @var{musicexpr}
1438 This means that @var{musicexpr} should be interpreted within a context
1439 of type @var{contexttype} (with name @var{contextname} if specified).
1440 If no such context exists, it will be created:
1442 @lilypond[verbatim,raggedright]
1444 \notes \relative c'' {
1445 c4 <<d4 \context Staff = "another" e4>> f
1451 In this example, the @code{c} and @code{d} are printed on the default
1452 staff. For the @code{e}, a context @code{Staff} called @code{another}
1453 is specified; since that does not exist, a new context is created.
1454 Within @code{another}, a (default) Voice context is created for the
1455 @code{e4}. A context is ended when when all music referring it has
1456 finished, so after the third quarter, @code{another} is removed.
1458 The @code{\new} construction creates a context with a
1459 generated, unique @var{contextname}. An expression with
1460 @code{\new} always leads to a new context. This is convenient
1461 for creating multiple staves, multiple lyric lines, etc.
1463 When using automatic staff changes, automatic phrasing, etc., the
1464 context names have special meanings, so @code{\new} cannot be
1468 @node Default contexts
1469 @subsection Default contexts
1471 Every top level music is interpreted by the @code{Score} context; in
1472 other words, you may think of @code{\score} working like
1476 \context Score @var{music}
1480 Music expressions inherit their context from the enclosing music
1481 expression. Hence, it is not necessary to explicitly specify
1482 @code{\context} for most expressions. In
1483 the following example, only the sequential expression has an explicit
1484 context. The notes contained therein inherit the @code{goUp} context
1485 from the enclosing music expression.
1487 @lilypond[verbatim,raggedright]
1488 \notes \context Voice = goUp { c'4 d' e' }
1492 Second, contexts are created automatically to be able to interpret the
1493 music expressions. Consider the following example:
1495 @lilypond[verbatim,raggedright]
1496 \score { \notes { c'4-( d' e'-) } }
1500 The sequential music is interpreted by the Score context initially,
1501 but when a note is encountered, contexts are setup to accept that
1502 note. In this case, a @code{Voice}, and @code{Staff}
1503 context are created. The rest of the sequential music is also
1504 interpreted with the same @code{Voice}, and
1505 @code{Staff} context, putting the notes on the same staff, in the same
1508 @node Context properties
1509 @subsection Context properties
1511 Contexts have properties. These properties are set from the @file{.ly}
1512 file using the following expression:
1513 @cindex context properties
1514 @cindex properties, context
1517 \set @var{contextname}.@var{propname} = @var{value}
1521 Sets the @var{propname} property of the context @var{contextname} to
1522 the specified Scheme expression @var{value}. Both @var{propname} and
1523 @var{contextname} are strings, which can often be written unquoted.
1526 Properties that are set in one context are inherited by all of the
1527 contained contexts. This means that a property valid for the
1528 @internalsref{Voice} context can be set in the @internalsref{Score} context
1529 (for example) and thus take effect in all @internalsref{Voice} contexts.
1531 Properties can be unset using the following statement.
1533 \unset @var{contextname}.@var{propname}
1536 @cindex properties, unsetting
1537 @cindex @code{\unset}
1540 This removes the definition of @var{propname} in @var{contextname}. If
1541 @var{propname} was not defined in @var{contextname} (but was inherited
1542 from a higher context), then this has no effect.
1544 If @var{contextname} is left out, then it defaults to the current
1545 ``bottom'' context: this is a context like @internalsref{Voice} that
1546 cannot contain any other contexts.
1549 @node Defining contexts
1550 @subsection Defining contexts
1552 @cindex context definition
1553 @cindex translator definition
1555 The most common way to create a new context definition is by extending
1556 an existing one. An existing context from the paper block is copied
1557 by referencing a context identifier:
1562 @var{context-identifier}
1568 Every predefined context has a standard identifier. For example, the
1569 @code{Staff} context can be referred to as @code{\StaffContext}.
1571 The context can then be modified by setting or changing properties,
1576 Stem \set #'thickness = #2.0
1577 defaultBarType = #"||"
1580 These assignments happen before interpretation starts, so a property
1581 command will override any predefined settings.
1587 It is not possible to collect multiple property assignments in a
1588 variable, and apply to one @code{\context} definition by
1589 referencing that variable.
1591 @node Changing contexts locally
1592 @subsection Changing contexts locally
1595 Extending an existing context can also be done locally. A piece of
1596 music can be interpreted in a changed context by using the following syntax
1600 @var{context modifications}
1604 These statements comes between @code{\new} or @code{\context} and the
1605 music to be interpreted. The @var{context modifications} property
1606 settings and @code{\remove}, @code{\consists} and @code{\consistsend}
1607 commands. The syntax is similar to the @code{\context} block.
1609 The following example shows how a staff is created with bigger spaces,
1610 and without a @code{Clef_engraver}.
1612 @lilypond[relative=1,fragment,verbatim]
1614 \new Staff { c4 es4 g2 }
1616 \override StaffSymbol #'staff-space = #(magstep 1.5)
1618 \remove "Clef_engraver"
1626 The command @code{\with} has no effect on contexts that already
1630 @node Engravers and performers
1631 @subsection Engravers and performers
1634 Each context is composed of a number of building blocks, or plug-ins
1635 called engravers. An engraver is a specialized C++ class that is
1636 compiled into the executable. Typically, an engraver is responsible
1637 for one function: the @code{Slur_engraver} creates only @code{Slur}
1638 objects, and the @code{Skip_event_swallow_translator} only swallows
1639 (silently gobbles) @code{SkipEvent}s.
1646 An existing context definition can be changed by adding or removing an
1647 engraver. The syntax for these operations is
1649 \consists @var{engravername}
1650 \remove @var{engravername}
1653 @cindex @code{\consists}
1654 @cindex @code{\remove}
1657 Here @var{engravername} is a string, the name of an engraver in the
1658 system. In the following example, the @code{Clef_engraver} is removed
1659 from the Staff context. The result is a staff without a clef, where
1660 the middle C is at its default position, the center line:
1662 @lilypond[verbatim,raggedright]
1670 \remove Clef_engraver
1676 A list of all engravers is in the internal documentation,
1677 see @internalsref{Engravers}.
1679 @node Defining new contexts
1680 @subsection Defining new contexts
1683 It is also possible to define new contexts from scratch. To do this,
1684 you must define give the new context a name. In the following
1685 example, a very simple Staff context is created: one that will put
1686 note heads on a staff symbol.
1690 \type "Engraver_group_engraver"
1693 \consists "Staff_symbol_engraver"
1694 \consists "Note_head_engraver"
1695 \consistsend "Axis_group_engraver"
1700 The argument of @code{\type} is the name for a special engraver that
1701 handles cooperation between simple engravers such as
1702 @code{Note_head_engraver} and @code{Staff_symbol_engraver}. This
1703 should always be @code{Engraver_group_engraver} (unless you are
1704 defining a Score context from scratch, in which case
1705 @code{Score_engraver} must be used).
1707 The complete list of context modifiers is the following:
1709 @item @code{\alias} @var{alternate-name}:
1710 This specifies a different name. In the above example,
1711 @code{\set Staff.X = Y} will also work on @code{SimpleStaff}s.
1713 @item @code{\consistsend} @var{engravername}:
1714 Analogous to @code{\consists}, but makes sure that
1715 @var{engravername} is always added to the end of the list of
1718 Engravers that group context objects into axis groups or alignments
1719 need to be at the end of the list. @code{\consistsend} insures that
1720 engravers stay at the end even if a user adds or removes engravers.
1722 @item @code{\accepts} @var{contextname}:
1723 This context can contains @var{contextname} contexts. The first
1724 @code{\accepts} is created as a default context when events (e.g. notes
1725 or rests) are encountered.
1727 @item @code{\denies}:
1728 The opposite of @code{\accepts}.
1730 @item @code{\name} @var{contextname}:
1731 This sets the type name of the context, e.g. @code{Staff},
1732 @code{Voice}. If the name is not specified, the translator will not
1741 @node Output details
1742 @section Output details
1744 The default output format is La@TeX{}, which should be run
1745 through La@TeX{}. Using the option @option{-f}
1746 (or @option{--format}) other output formats can be selected also, but
1747 none of them work reliably.
1749 Now the music is output system by system (a `system' consists of all
1750 staves belonging together). From @TeX{}'s point of view, a system is an
1751 @code{\hbox} which contains a lowered @code{\vbox} so that it is centered
1752 vertically on the baseline of the text. Between systems,
1753 @code{\interscoreline} is inserted vertically to have stretchable space.
1754 The horizontal dimension of the @code{\hbox} is given by the
1755 @code{linewidth} parameter from LilyPond's @code{\paper} block.
1757 After the last system LilyPond emits a stronger variant of
1758 @code{\interscoreline} only if the macro
1759 @code{\lilypondpaperlastpagefill} is not defined (flushing the systems
1760 to the top of the page). You can avoid that by setting the variable
1761 @code{lastpagefill} in LilyPond's @code{\paper} block.
1763 It is possible to fine-tune the vertical offset further by defining the
1764 macro @code{\lilypondscoreshift}:
1767 \def\lilypondscoreshift@{0.25\baselineskip@}
1771 where @code{\baselineskip} is the distance from one text line to the next.
1773 Here an example how to embed a small LilyPond file @code{foo.ly} into
1774 running La@TeX{} text without using the @code{lilypond-book} script
1775 (@pxref{lilypond-book manual}):
1778 \documentclass@{article@}
1780 \def\lilypondpaperlastpagefill@{@}
1782 \def\lilypondscoreshift@{0.25\baselineskip@}
1785 This is running text which includes an example music file
1791 The file @file{foo.tex} has been simply produced with
1797 The call to @code{\lineskip} assures that there is enough vertical space
1798 between the LilyPond box and the surrounding text lines.