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
24 objects. For example, changing stem directions, or the location of
27 @item Context: changing aspects of the translation from music events to
28 notation. For example, giving each staff a separate time signature.
30 @item Global layout: changing the appearance of the spacing, line
31 breaks and page dimensions.
34 Then, there are separate systems for typesetting text (like
35 @emph{ritardando}) and selecting different fonts. This chapter also
38 Internally, LilyPond uses Scheme (a LISP dialect) to provide
39 infrastructure. Overriding layout decisions in effect accesses the
40 program internals, so it is necessary to learn a (very small) subset
41 of Scheme. That is why this chapter starts with a short tutorial on
42 entering numbers, lists, strings and symbols in Scheme.
48 * Fine tuning layout::
52 * Interpretation context::
57 @section Scheme tutorial
61 @cindex Scheme, in-line code
62 @cindex accessing Scheme
63 @cindex evaluating Scheme
66 LilyPond uses the Scheme programming language, both as part of the
67 input syntax, and as internal mechanism to glue together modules of
68 the program. This section is a very brief overview of entering data in
69 Scheme.@footnote{If you want to know more about Scheme, see
70 @uref{http://www.schemers.org}.}
72 The most basic thing of a language is data: numbers, character
73 strings, lists, etc. Here is a list of data types that are relevant to
78 Boolean values are True or False. The Scheme for True is @code{#t}
79 and False is @code{#f}.
81 Numbers are entered in the standard fashion,
82 @code{1} is the (integer) number one, while @code{-1.5} is a
83 floating point number (a non-integer number).
85 Strings are enclosed in double quotes,
90 Strings may span several lines
97 Quotation marks and newlines can also be added with so-called escape
98 sequences. The string @code{a said "b"} is entered as
103 Newlines and backslashes are escaped with @code{\n} and @code{\\}
108 In a music file, snippets of Scheme code are introduced with the hash
109 mark @code{#}. So, the previous examples translated in LilyPondese are
120 For the rest of this section, we will assume that the data is entered
121 in a music file, so we add @code{#}s everywhere.
123 Scheme can be used to do calculations. It uses @emph{prefix}
124 syntax. Adding 1 and 2 is written as @code{(+ 1 2)} rather than the
132 The arrow @result{} shows that the result of evaluating @code{(+ 1 2)}
133 is @code{3}. Calculations may be nested: the result of a function may
134 be used for another calculation.
142 These calculations are examples of evaluations: an expression (like
143 @code{(* 3 4)} is replaced by its value @code{12}. A similar thing
144 happens with variables. After defining a variable
150 variables can also be used in expressions, here
153 twentyFour = #(* 2 twelve)
156 the number 24 is stored in the variable @code{twentyFour}.
158 The @emph{name} of a variable is also an expression, similar to a
159 number or a string. It is entered as
165 The quote mark @code{'} prevents Scheme interpreter from substituting
166 @code{24} for the @code{twentyFour}. Instead, we get the name
169 This syntax will be used very frequently, since many of the layout
170 tweaks involve assigning (Scheme) values to internal variables, for
174 \override Stem #'thickness = #2.6
177 This instruction adjusts the appearance of stems. The value @code{2.6}
178 is put into a the @code{thickness} variable of a @code{Stem}
179 object. This makes stems almost twice as thick as their normal size.
180 To distinguish between variables defined in input files (like
181 @code{twentyFour} in the example above), and internal variables, we
182 will call the latter ``properties.'' So, the stem object has a
183 @code{thickness} property.
185 Two-dimensional offsets (X and Y coordinates) as well as object sizes
186 (intervals with a left and right point) are entered as @code{pairs}. A
187 pair@footnote{In Scheme terminology, the pair is called @code{cons},
188 and its two elements are called car and cdr respectively.} is entered
189 as @code{(first . second)}, and like symbols, they must be quoted,
192 \override TextScript #'extra-offset = #'(1 . 2)
195 This assigns the pair (1, 2) to @code{extra-offset} variable of the
196 TextScript object. This moves the object 1 staff space to the right,
199 The two elements of a pair may be arbitrary values, for example
204 #'("blah-blah" . 3.14159265)
207 A list is entered by enclosing its elements in parentheses, and adding
208 a quote. For example,
214 We have been using lists all along. A calculation, like @code{(+ 1
215 2)} is also a list (containing the symbol @code{+} and the numbers 1
216 and 2). For entering lists, use a quote @code{'} and for
217 calculations, do not use a quote.
219 Inside a quoted list or pair, there is no need to quote anymore. The
220 following is a pair of symbols, a list of symbols and a list of lists
225 #'(staff clef key-signature)
233 When music is printed, a lot of things notation elements must be added
234 to the input, which is often bare bones. For example, compare the
235 input and output of the following example
237 @lilypond[verbatim,relative=2]
241 The input is rather sparse, but in the output, bar lines, accidentals,
242 clef and time signature are added. LilyPond @emph{interprets} the
243 input. During this step, the musical information is inspected in time
244 order, similar to reading a score from left to right. While reading,
245 the program remembers where measure boundaries are, and what pitches
246 need explicit accidentals.
248 This information can be present on several levels. For example, the
249 effect of an accidental is limited to a single stave, while a bar line
250 must be synchronized across the entire score. To match this
251 hierarchy, LilyPond's interpretation step is hierarchical. Properties
252 are maintained `interpretation contexts', like Voice, Staff and Score,
253 and each context can have different @emph{properties}, variables that
254 are contained in a context.
257 * Changing context properties on the fly ::
258 * context property defaults ::
259 * which properties to change::
262 @node Changing context properties on the fly
263 @subsection Changing context properties on the fly
265 Such variables can be changed during the interpretation step.
266 This is achieved by inserting the @code{\set} command in the music,
269 @code{\set }[@var{context}]@code{.}@var{prop}@code{ = #}@var{value}
273 @lilypond[verbatim,relative=2]
275 \set Score.skipBars = ##t
279 This command skips measures that have no notes. The result is that
280 multi rests are condensed. The value assigned is a Scheme object. In
281 this case, it is @code{#t}, the boolean True value.
283 If the @var{context} argument is left out, then the current
284 bottom-most context (typically ChordNames, Voice or Lyrics) is used.
287 @lilypond[verbatim,relative=2]
289 \set autoBeaming = ##f
294 the @var{context} argument to @code{\set} is left out, and the current
295 @internalsref{Voice} is used. Contexts are hierarchical, so if a
296 bigger context was specified, for example @code{Staff}, then the
297 change would apply to all Voices in the current stave.
299 There is also an @code{\unset} command,
301 @code{\set }[@var{context}]@code{.}@var{prop}
305 which removes the definition of @var{prop}. This command only removes
310 \set staff.autobeaming = ##f
311 \unset voice.autobeaming
315 the current voice does not have the property, and the definition at
316 staff level remains intact.
318 @node context property defaults
319 @subsection context property defaults
323 @node which properties to change
324 @subsection which properties to change
327 There are many different properties. Not all of them are listed in
328 this manual. However, the program reference lists them all in the
329 section @internalsref{Context-properties}, and most properties are
330 demonstrated in one of the
332 @uref{../../../input/test/out-www/collated-files.html,tips-and-tricks}
340 @node Fine tuning layout
341 @section Fine tuning layout
343 Sometimes it is necessary to change music layout by hand. When music
344 is formatted, layout objects are created for each symbol. For
345 example, every clef and every note head is represented by a layout
346 object. These layout objects also carry variables, which we call
347 @emph{layout properties}. By changing these variables from their
348 values, we can alter the look of a formatted score:
350 @lilypond[verbatim,relative]
352 \override Stem #'thickness = #3.0
357 In the example shown here, the layout property @code{thickness} (a
358 symbol) is set to 3 in the @code{Stem} layout objects of the current
359 As a result, the notes following @code{\override} have thicker
362 For the most part, a manual override is needed only on a case by
363 case basis and not for all subsequent instances of the altered
364 property. To accomplish this, simply prefix @code{\once} to the
365 @code{\override} statement and the override will apply only once,
366 immediately reverting to its default setting, i.e.
369 \once \override Stem #'thickness = #3.0
374 \once \override Stem #'thickness = #3.0
379 Some overrides are so common that predefined commands are provided as
380 a short cut. For example, @code{\slurUp} and @code{\stemDown}. These
381 commands are described in
385 @ref{Notation manual}, under the sections for slurs and stems
388 The exact tuning possibilities for each type of layout object are
389 documented in the program reference of the respective
390 object. However, many layout objects share properties, which can be
391 used to apply generic tweaks. We mention a couple of these:
394 @item The @code{extra-offset} property, which
395 @cindex @code{extra-offset}
396 has a pair of numbers as value, moves around objects in the printout.
397 The first number controls left-right movement; a positive number will
398 move the object to the right. The second number controls up-down
399 movement; a positive number will move it higher. The units of these
400 offsets are staff-spaces. The @code{extra-offset} property is a
401 low-level feature: the formatting engine is completely oblivious to
404 In the following example, the second fingering is moved a little to
405 the left, and 1.8 staff space downwards:
407 @cindex setting object properties
409 @lilypond[relative=1,verbatim]
412 \once \override Fingering
413 #'extra-offset = #'(-0.3 . -1.8)
418 Setting the @code{transparent} property will cause an object to be printed
419 in `invisible ink': the object is not printed, but all its other
420 behavior is retained. The object still takes up space, it takes part in
421 collisions, and slurs, and ties and beams can be attached to it.
423 @cindex transparent objects
424 @cindex removing objects
425 @cindex invisible objects
426 The following example demonstrates how to connect different voices
427 using ties. Normally, ties only connect two notes in the same
428 voice. By introducing a tie in a different voice, and blanking a stem
429 in that voice, the tie appears to cross voices:
431 @lilypond[fragment,relative=1,verbatim]
433 \once \override Stem #'transparent = ##t
441 The @code{padding} property for objects with
442 @cindex @code{padding}
443 @code{side-position-interface} can be set to increase distance between
444 symbols that are printed above or below notes. We only give an
445 example; a more elaborate explanation is in @ref{Constructing a
448 @lilypond[relative=1,verbatim]
450 \override Script #'padding = #3
456 More specific overrides are also possible. The notation manual
457 discusses in depth how to figure out these statements for yourself, in
464 @section Tuning output
466 There are situations where default layout decisions are not
467 sufficient. In this section we discuss ways to override these
470 Formatting is internally done by manipulating so called objects
471 (graphic objects). Each object carries with it a set of properties
472 (object or layout properties) specific to that object. For example, a
473 stem object has properties that specify its direction, length and
476 The most direct way of tuning the output is by altering the values of
477 these properties. There are two ways of doing that: first, you can
478 temporarily change the definition of one type of object, thus
479 affecting a whole set of objects. Second, you can select one specific
480 object, and set a layout property in that object.
482 Do not confuse layout properties with translation
483 properties. Translation properties always use a mixed caps style
484 naming, and are manipulated using @code{\set} and @code{\unset}:
486 \set Context.propertyName = @var{value}
489 Layout properties are use Scheme style variable naming, i.e. lower
490 case words separated with dashes. They are symbols, and should always
491 be quoted using @code{#'}. For example, this could be an imaginary
492 layout property name:
494 #'layout-property-name
500 * Constructing a tweak::
501 * Selecting font sizes::
508 @subsection Tuning objects
510 @cindex object description
512 The definition of an object is a list of default object
513 properties. For example, the definition of the Stem object (available
514 in @file{scm/define-grobs.scm}), includes the following definitions
515 for @internalsref{Stem}:
519 (beamed-lengths . (3.5 3.5 3.5 4.5 5.0))
520 (Y-extent-callback . ,Stem::height)
525 Adding variables on top of this existing definition overrides the
526 system default, and alters the resulting appearance of the layout
532 Changing a variable for only one object is commonly achieved with
536 \once \override @var{context}.@var{objectname}
537 @var{symbol} = @var{value}
539 Here @var{symbol} is a Scheme expression of symbol type, @var{context}
540 and @var{objectname} is a string and @var{value} is a Scheme expression.
541 This command applies a setting only during one moment in the score.
543 In the following example, only one @internalsref{Stem} object is
544 changed from its original setting:
546 @lilypond[verbatim,fragment,relative=1]
548 \once \override Voice.Stem #'thickness = #4
554 For changing more objects, the same command, without @code{\once} can
557 \override @var{context}.@var{objectname} @var{symbol} = @var{value}
559 This command adds @code{@var{symbol} = @var{value}} to the definition
560 of @var{objectname} in the context @var{context}, and this definition
561 stays in place until it is removed.
563 An existing definition may be removed by the following command:
566 \property @var{context}.@var{objectname} \revert @var{symbol}
572 c'4 \override Stem #'thickness = #4.0
574 c'4 \revert Stem #'thickness
580 Reverting a setting which was not set in the first place has no
586 Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
587 @internalsref{PropertySet}, @internalsref{All-backend-properties}, and
588 @internalsref{All-layout-objects}.
593 The back-end is not very strict in type-checking object properties.
594 Cyclic references in Scheme values for properties can cause hangs
598 @node Constructing a tweak
599 @subsection Constructing a tweak
602 @cindex internal documentation
603 @cindex finding graphical objects
604 @cindex graphical object descriptions
606 @cindex @code{\override}
608 @cindex internal documentation
612 Three pieces of information are required to use @code{\override} and
613 @code{\set}: the name of the layout object, the context and the name
614 of the property. We demonstrate how to glean this information from
615 the notation manual and the program reference.
617 The generated documentation is a set of HTML pages which should be
618 included if you installed a binary distribution, typically in
619 @file{/usr/share/doc/lilypond}. They are also available on the web:
620 go to the @uref{http://lilypond.org,LilyPond website}, click
621 ``Documentation'', select the correct version, and then click
622 ``Program reference.'' It is advisable to bookmark the local HTML
623 files. They will load faster than the ones on the web and matches the
624 version of LilyPond you are using.
628 @c [TODO: revise for new site.]
630 Suppose we want to move the fingering indication in the fragment
633 @lilypond[relative=2,verbatim]
639 If you visit the documentation of @code{Fingering} (in @ref{Fingering
640 instructions}), you will notice that there is written:
645 Internals: @internalsref{FingerEvent} and @internalsref{Fingering}.
652 In other words, the fingerings once entered, are internally stored as
653 @code{FingerEvent} music objects. When printed, a @code{Fingering}
654 layout object is created for every @code{FingerEvent}.
656 The Fingering object has a number of different functions, and each of
657 those is captured in an interface. The interfaces are listed under
658 @internalsref{Fingering} in the program reference.
662 The @code{Fingering} object has a fixed size
663 (@internalsref{item-interface}), the symbol is a piece of text
664 (@internalsref{text-interface}), whose font can be set
665 (@internalsref{font-interface}). It is centered horizontally
666 (@internalsref{self-alignment-interface}), it is placed vertically
667 next to other objects (@internalsref{side-position-interface}), and
668 its placement is coordinated with other scripts
669 (@internalsref{text-script-interface}). It also has the standard
670 @internalsref{grob-interface} (grob stands for Graphical object)
672 @cindex graphical object
673 @cindex layout object
674 @cindex object, layout
675 with all the variables that come with
676 it. Finally, it denotes a fingering instruction, so it has
677 @internalsref{finger-interface}.
679 For the vertical placement, we have to look under
680 @code{side-position-interface}:
682 @code{side-position-interface}
684 Position a victim object (this one) next to other objects (the
685 support). In this case, the property @code{direction} signifies where to put the
686 victim object relative to the support (left or right, up or down?)
691 below this description, the variable @code{padding} is described as
695 (dimension, in staff space)
697 add this much extra space between objects that are next to each
698 other. Default value: @code{0.6}
702 By increasing the value of @code{padding}, we can move away the
703 fingering. The following command inserts 3 staff spaces of white
704 between the note and the fingering:
706 \once \override Fingering #'padding = #3
709 Inserting this command before the Fingering object is created,
710 i.e. before @code{c2}, yields the following result:
712 @lilypond[relative=2,fragment,verbatim]
713 \once \override Fingering
720 The context name @code{Voice} in the example above can be determined
721 as follows. In the documentation for @internalsref{Fingering}, it says
723 Fingering grobs are created by: @internalsref{Fingering_engraver} @c
726 Clicking @code{Fingering_engraver} shows the documentation of
727 the module responsible for interpreting the fingering instructions and
728 translating them to a @code{Fingering} object. Such a module is called
729 an @emph{engraver}. The documentation of the @code{Fingering_engraver}
732 Fingering_engraver is part of contexts: Voice
734 so tuning the settings for Fingering should be done with
736 \override Fingering @dots{}
739 Of course, the tweak may also done in a larger context than
740 @code{Voice}, for example, @internalsref{Staff} or
741 @internalsref{Score}.
745 Internals: the program reference also contains alphabetical lists of
746 @internalsref{Contexts}, @internalsref{All-layout-objects} and
747 @internalsref{Music-expressions}, so you can also find which objects
748 to tweak by browsing the internals document.
751 @node Selecting font sizes
752 @subsection Selecting font sizes
754 The most common thing to change about the appearance of fonts is their
755 size. The font size of any context can be easily changed by setting
756 the @code{fontSize} property for that context. Its value is a number:
757 negative numbers make the font smaller, positive numbers larger. An
758 example is given below:
760 @lilypond[fragment,relative=1,verbatim]
761 c4 c4 \set fontSize = #-3
764 This command will set @code{font-size} (see below) in all layout
765 objects in the current context. It does not change the size of
766 variable symbols, such as beams or slurs.
768 The font size is set by modifying the @code{font-size} property. Its
769 value is a number indicating the size relative to the standard size.
770 Each step up is an increase of approximately 12% of the font size. Six
771 steps is exactly a factor two. The Scheme function @code{magstep}
772 converts a @code{font-size} number to a scaling factor.
774 LilyPond has fonts in different design sizes: the music fonts for
775 smaller sizes are chubbier, while the text fonts are relatively wider.
776 Font size changes are achieved by scaling the design size that is
777 closest to the desired size.
779 The @code{font-size} mechanism does not work for fonts selected
780 through @code{font-name}. These may be scaled with
781 @code{font-magnification}.
784 One of the uses of @code{fontSize} is to get smaller symbols for cue
785 notes. An elaborate example of those is in
786 @inputfileref{input/test,cue-notes.ly}.
788 @cindex @code{font-style}
792 The following commands set @code{fontSize} for the current voice.
796 @cindex @code{\small}
798 @cindex @code{\normalsize}
803 @cindex magnification
808 @subsection Font selection
810 Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
811 can also be adjusted with a more fine-grained mechanism. By setting
812 the object properties described below, you can select a different font;
813 all three mechanisms work for every object that supports
814 @code{font-interface}:
818 @item @code{font-encoding}
819 is a symbol that sets layout of the glyphs. Choices include
820 @code{text} for normal text, @code{braces} (for piano staff braces),
821 @code{music} (the standard music font, including ancient glyphs),
822 @code{dynamic} (for dynamic signs) and @code{number} for the number
826 @item @code{font-family}
827 is a symbol indicating the general class of the typeface. Supported are
828 @code{roman} (Computer Modern), @code{sans} and @code{typewriter}
830 @item @code{font-shape}
831 is a symbol indicating the shape of the font, there are typically
832 several font shapes available for each font family. Choices are
833 @code{italic}, @code{caps} and @code{upright}.
835 @item @code{font-series}
836 is a symbol indicating the series of the font. There are typically several
837 font series for each font family and shape. Choices are @code{medium}
842 Fonts selected in the way sketched above come from a predefined style
845 The font used for printing a object can be selected by setting
846 @code{font-name}, e.g.
848 \override Staff.TimeSignature
849 #'font-name = #"cmr17"
853 Any font can be used, as long as it is available to @TeX{}. Possible
854 fonts include foreign fonts or fonts that do not belong to the
855 Computer Modern font family. The size of fonts selected in this way
856 can be changed with the @code{font-magnification} property. For
857 example, @code{2.0} blows up all letters by a factor 2 in both
861 @cindex font magnification
867 Init files: @file{ly/declarations-init.ly} contains hints how new
868 fonts may be added to LilyPond.
872 No style sheet is provided for other fonts besides the @TeX{}
873 Computer Modern family.
875 @cindex font selection
876 @cindex font magnification
877 @cindex @code{font-interface}
888 LilyPond has an internal mechanism to typeset texts. You can access it
889 with the keyword @code{\markup}. Within markup mode, you can enter texts
890 similar to lyrics: simply enter them, surrounded by spaces:
893 @lilypond[verbatim,fragment,relative=1]
895 c1_\markup { hi there }
896 c1^\markup { hi \bold there, is \italic anyone home? }
899 @cindex font switching
901 The markup in the example demonstrates font switching commands. The
902 command @code{\bold} and @code{\italic} only apply to the first
903 following word; enclose a set of texts with braces to apply a command
906 \markup @{ \bold @{ hi there @} @}
910 For clarity, you can also do this for single arguments, e.g.
913 \markup { is \italic { anyone } home }
916 @cindex font size, texts
919 In markup mode you can compose expressions, similar to mathematical
920 expressions, XML documents and music expressions. The braces group
921 notes into horizontal lines. Other types of lists also exist: you can
922 stack expressions grouped with @code{<}, and @code{>} vertically with
923 the command @code{\column}. Similarly, @code{\center-align} aligns
924 texts by their center lines:
926 @lilypond[verbatim,fragment,relative=1]
927 c1^\markup { \column < a bbbb c > }
928 c1^\markup { \center-align < a bbbb c > }
929 c1^\markup { \line < a b c > }
933 Markups can be stored in variables, and these variables
934 may be attached to notes, like
936 allegro = \markup { \bold \large { Allegro } }
937 \notes { a^\allegro b c d }
941 Some objects have alignment procedures of their own, which cancel out
942 any effects of alignments applied to their markup arguments as a
943 whole. For example, the @internalsref{RehearsalMark} is horizontally
944 centered, so using @code{\mark \markup @{ \left-align .. @}} has no
947 Similarly, for moving whole texts over notes with
948 @code{\raise}, use the following trick:
950 "" \raise #0.5 raised
953 The text @code{raised} is now raised relative to the empty string
954 @code{""} which is not visible. Alternatively, complete objects can
955 be moved with layout properties such as @code{padding} and
962 Init files: @file{scm/new-markup.scm}.
967 Text layout is ultimately done by @TeX{}, which does kerning of
968 letters. LilyPond does not account for kerning, so texts will be
969 spaced slightly too wide.
971 Syntax errors for markup mode are confusing.
973 Markup texts cannot be used in the titling of the @code{\header}
974 field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
980 * Overview of text markup commands::
983 @node Overview of text markup commands
984 @subsection Overview of text markup commands
986 @include markup-commands.tely
990 @section Global layout
992 The global layout determined by three factors: the page layout, the
993 line breaks and the spacing. These all influence each other. The
994 choice of spacing determines how densely each system of music is set,
995 which influences where line breaks breaks are chosen, and thus
996 ultimately how many pages a piece of music takes. This section
997 explains how to tune the algorithm for spacing.
999 Globally spoken, this procedure happens in three steps: first,
1000 flexible distances (``springs'') are chosen, based on durations. All
1001 possible line breaking combination are tried, and the one with the
1002 best results---a layout that has uniform density and requires as
1003 little stretching or cramping as possible---is chosen. When the score
1004 is processed by @TeX{}, each page is filled with systems, and page breaks
1005 are chosen whenever the page gets full.
1010 * Vertical spacing::
1011 * Horizontal spacing::
1018 @node Vertical spacing
1019 @subsection Vertical spacing
1021 @cindex vertical spacing
1022 @cindex distance between staves
1023 @cindex staff distance
1024 @cindex between staves, distance
1025 @cindex staves per page
1026 @cindex space between staves
1028 The height of each system is determined automatically by LilyPond, to
1029 keep systems from bumping into each other, some minimum distances are
1030 set. By changing these, you can put staves closer together, and thus
1031 put more systems onto one page.
1033 Normally staves are stacked vertically. To make
1034 staves maintain a distance, their vertical size is padded. This is
1035 done with the property @code{minimumVerticalExtent}. It takes a pair
1036 of numbers, so if you want to make it smaller from its, then you could
1039 \set Staff.minimumVerticalExtent = #'(-4 . 4)
1041 This sets the vertical size of the current staff to 4 staff spaces on
1042 either side of the center staff line. The argument of
1043 @code{minimumVerticalExtent} is interpreted as an interval, where the
1044 center line is the 0, so the first number is generally negative. The
1045 staff can be made larger at the bottom by setting it to @code{(-6
1048 The piano staves are handled a little differently: to make cross-staff
1049 beaming work correctly, it is necessary that the distance between staves
1050 is fixed beforehand. This is also done with a
1051 @internalsref{VerticalAlignment} object, created in
1052 @internalsref{PianoStaff}. In this object the distance between the
1053 staves is fixed by setting @code{forced-distance}. If you want to
1054 override this, use a @code{\context} block as follows:
1059 \override VerticalAlignment #'forced-distance = #9
1064 This would bring the staves together at a distance of 9 staff spaces,
1065 measured from the center line of each staff.
1069 Internals: Vertical alignment of staves is handled by the
1070 @internalsref{VerticalAlignment} object.
1075 @node Horizontal spacing
1076 @subsection Horizontal Spacing
1078 The spacing engine translates differences in durations into
1079 stretchable distances (``springs'') of differing lengths. Longer
1080 durations get more space, shorter durations get less. The shortest
1081 durations get a fixed amount of space (which is controlled by
1082 @code{shortest-duration-space} in the @internalsref{SpacingSpanner} object).
1083 The longer the duration, the more space it gets: doubling a
1084 duration adds a fixed amount (this amount is controlled by
1085 @code{spacing-increment}) of space to the note.
1087 For example, the following piece contains lots of half, quarter and
1088 8th notes, the eighth note is followed by 1 note head width (NHW).
1089 The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
1090 @lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8
1094 Normally, @code{shortest-duration-space} is set to 1.2, which is the
1095 width of a note head, and @code{shortest-duration-space} is set to
1096 2.0, meaning that the shortest note gets 2 NHW (i.e. 2 times
1097 @code{shortest-duration-space}) of space. For normal notes, this space
1098 is always counted from the left edge of the symbol, so the shortest
1099 notes are generally followed by one NHW of space.
1101 If one would follow the above procedure exactly, then adding a single
1102 32th note to a score that uses 8th and 16th notes, would widen up the
1103 entire score a lot. The shortest note is no longer a 16th, but a 32nd,
1104 thus adding 1 NHW to every note. To prevent this, the
1105 shortest duration for spacing is not the shortest note in the score,
1106 but the most commonly found shortest note. Notes that are even
1107 shorter this are followed by a space that is proportional to their
1108 duration relative to the common shortest note. So if we were to add
1109 only a few 16th notes to the example above, they would be followed by
1112 @lilypond[fragment,verbatim,relative=2]
1113 c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4
1116 The most common shortest duration is determined as follows: in every
1117 measure, the shortest duration is determined. The most common short
1118 duration, is taken as the basis for the spacing, with the stipulation
1119 that this shortest duration should always be equal to or shorter than
1120 1/8th note. The shortest duration is printed when you run lilypond
1121 with @code{--verbose}. These durations may also be customized. If you
1122 set the @code{common-shortest-duration} in
1123 @internalsref{SpacingSpanner}, then this sets the base duration for
1124 spacing. The maximum duration for this base (normally 1/8th), is set
1125 through @code{base-shortest-duration}.
1127 @cindex @code{common-shortest-duration}
1128 @cindex @code{base-shortest-duration}
1129 @cindex @code{stem-spacing-correction}
1130 @cindex @code{spacing}
1132 In the introduction it was explained that stem directions influence
1133 spacing. This is controlled with @code{stem-spacing-correction}
1134 property in @internalsref{NoteSpacing}, which are generated for every
1135 @internalsref{Voice} context. The @code{StaffSpacing} object
1136 (generated at @internalsref{Staff} context) contains the same property
1137 for controlling the stem/bar line spacing. The following example
1138 shows these corrections, once with default settings, and once with
1139 exaggerated corrections:
1145 \override Staff.NoteSpacing #'stem-spacing-correction
1147 \override Staff.StaffSpacing #'stem-spacing-correction
1152 \paper { raggedright = ##t } }
1155 @cindex SpacingSpanner, overriding properties
1157 Properties of the @internalsref{SpacingSpanner} must be overridden
1158 from the @code{\paper} block, since the @internalsref{SpacingSpanner} is
1159 created before any property commands are interpreted.
1161 \paper @{ \context @{
1163 SpacingSpanner \override #'spacing-increment = #3.0
1170 Internals: @internalsref{SpacingSpanner}, @internalsref{NoteSpacing},
1171 @internalsref{StaffSpacing}, @internalsref{SeparationItem}, and
1172 @internalsref{SeparatingGroupSpanner}.
1176 Spacing is determined on a score wide basis. If you have a score that
1177 changes its character (measured in durations) halfway during the
1178 score, the part containing the longer durations will be spaced too
1181 There is no convenient mechanism to manually override spacing.
1186 @subsection Font size
1188 @cindex font size, setting
1189 @cindex staff size, setting
1190 @cindex @code{paper} file
1192 The Feta font provides musical symbols at eight different
1193 sizes. Each font is tuned for a different staff size: at smaller sizes
1194 the font gets heavier, to match the relatively heavier staff lines.
1195 The recommended font sizes are listed in the following table:
1197 @multitable @columnfractions .25 .25 .25 .25
1200 @tab @b{staff height (pt)}
1201 @tab @b{staff height (mm)}
1243 @c modern rental material ?
1247 These fonts are available in any sizes. The context property
1248 @code{fontSize} and the layout property @code{staff-space} (in
1249 @internalsref{StaffSymbol}) can be used to tune size for individual
1250 staves. The size of individual staves are relative to the global size,
1251 which can be set in the following manner:
1254 #(set-global-staff-size 14)
1257 This sets the global default size to 14pt staff height, and scales all
1262 This manual: @ref{Selecting font sizes}.
1266 @subsection Line breaking
1269 @cindex breaking lines
1271 Line breaks are normally computed automatically. They are chosen such
1272 that lines look neither cramped nor loose, and that consecutive lines
1273 have similar density.
1275 Occasionally you might want to override the automatic breaks; you can
1276 do this by specifying @code{\break}. This will force a line break at
1277 this point. Line breaks can only occur at places where there are bar
1278 lines. If you want to have a line break where there is no bar line,
1279 you can force an invisible bar line by entering @code{\bar
1280 ""}. Similarly, @code{\noBreak} forbids a line break at a
1284 @cindex regular line breaks
1285 @cindex four bar music.
1287 For line breaks at regular intervals use @code{\break} separated by
1288 skips and repeated with @code{\repeat}:
1290 << \repeat unfold 7 @{
1291 s1 \noBreak s1 \noBreak
1292 s1 \noBreak s1 \break @}
1293 @emph{the real music}
1298 This makes the following 28 measures (assuming 4/4 time) be broken every
1299 4 measures, and only there.
1303 @code{\break}, @code{\noBreak}
1304 @cindex @code{\break}
1305 @cindex @code{\noBreak}
1309 Internals: @internalsref{BreakEvent}.
1313 @subsection Page layout
1316 @cindex breaking pages
1318 @cindex @code{indent}
1319 @cindex @code{linewidth}
1321 The most basic settings influencing the spacing are @code{indent} and
1322 @code{linewidth}. They are set in the @code{\paper} block. They
1323 control the indentation of the first line of music, and the lengths of
1326 If @code{raggedright} is set to true in the @code{\paper}
1327 block, then the lines are justified at their natural length. This
1328 useful for short fragments, and for checking how tight the natural
1332 @cindex vertical spacing
1334 The page layout process happens outside the LilyPond formatting
1335 engine: variables controlling page layout are passed to the output,
1336 and are further interpreted by @code{lilypond} wrapper program. It
1337 responds to the following variables in the @code{\paper} block. The
1338 spacing between systems is controlled with @code{interscoreline}, its
1339 default is 16pt. The distance between the score lines will stretch in
1340 order to fill the full page @code{interscorelinefill} is set to a
1341 positive number. In that case @code{interscoreline} specifies the
1344 @cindex @code{textheight}
1345 @cindex @code{interscoreline}
1346 @cindex @code{interscorelinefill}
1348 If the variable @code{lastpagefill} is defined,
1349 @c fixme: this should only be done if lastpagefill= #t
1350 systems are evenly distributed vertically on the last page. This
1351 might produce ugly results in case there are not enough systems on the
1352 last page. The @command{lilypond-book} command ignores
1353 @code{lastpagefill}. See @ref{lilypond-book manual} for more
1356 @cindex @code{lastpagefill}
1358 Page breaks are normally computed by @TeX{}, so they are not under
1359 direct control of LilyPond. However, you can insert a commands into
1360 the @file{.tex} output to instruct @TeX{} where to break pages. This
1361 is done by setting the @code{between-systems-strings} on the
1362 @internalsref{NonMusicalPaperColumn} where the system is broken.
1363 An example is shown in @inputfileref{input/regression,between-systems.ly}.
1364 The predefined command @code{\newpage} also does this.
1368 @cindex @code{papersize}
1370 To change the paper size, use the following Scheme code:
1373 #(set-paper-size "a4")
1380 @cindex @code{\newpage}
1386 In this manual: @ref{Invoking lilypond}.
1388 Examples: @inputfileref{input/regression,between-systems.ly}.
1390 Internals: @internalsref{NonMusicalPaperColumn}.
1394 LilyPond has no concept of page layout, which makes it difficult to
1395 reliably choose page breaks in longer pieces.
1398 @node Interpretation context
1399 @section Interpretation context
1402 * Creating contexts::
1403 * Default contexts::
1404 * Context properties::
1405 * Defining contexts::
1406 * Changing contexts locally::
1407 * Engravers and performers::
1408 * Defining new contexts::
1412 Interpretation contexts are objects that only exist during program
1413 run. During the interpretation phase (when @code{interpreting music}
1414 is printed on the standard output), the music expression in a
1415 @code{\score} block is interpreted in time order, the same order in
1416 which we hear and play the music. During this phase, the interpretation
1417 context holds the state for the current point within the music, for
1420 @item What notes are playing at this point?
1422 @item What symbols will be printed at this point?
1424 @item What is the current key signature, time signature, point within
1428 Contexts are grouped hierarchically: A @internalsref{Voice} context is
1429 contained in a @internalsref{Staff} context (because a staff can contain
1430 multiple voices at any point), a @internalsref{Staff} context is contained in
1431 @internalsref{Score}, @internalsref{StaffGroup}, or
1432 @internalsref{ChoirStaff} context.
1434 Contexts associated with sheet music output are called @emph{notation
1435 contexts}, those for sound output are called @emph{performance
1436 contexts}. The default definitions of the standard notation and
1437 performance contexts can be found in @file{ly/engraver-init.ly} and
1438 @file{ly/performer-init.ly}, respectively.
1441 @node Creating contexts
1442 @subsection Creating contexts
1443 @cindex @code{\context}
1444 @cindex context selection
1446 Contexts for a music expression can be selected manually, using one of
1447 the following music expressions:
1450 \new @var{contexttype} @var{musicexpr}
1451 \context @var{contexttype} [= @var{contextname}] @var{musicexpr}
1455 This means that @var{musicexpr} should be interpreted within a context
1456 of type @var{contexttype} (with name @var{contextname} if specified).
1457 If no such context exists, it will be created:
1459 @lilypond[verbatim,raggedright]
1461 \notes \relative c'' {
1462 c4 <<d4 \context Staff = "another" e4>> f
1468 In this example, the @code{c} and @code{d} are printed on the default
1469 staff. For the @code{e}, a context @code{Staff} called @code{another}
1470 is specified; since that does not exist, a new context is created.
1471 Within @code{another}, a (default) Voice context is created for the
1472 @code{e4}. A context is ended when when all music referring it has
1473 finished, so after the third quarter, @code{another} is removed.
1475 The @code{\new} construction creates a context with a
1476 generated, unique @var{contextname}. An expression with
1477 @code{\new} always leads to a new context. This is convenient
1478 for creating multiple staves, multiple lyric lines, etc.
1480 When using automatic staff changes, automatic phrasing, etc., the
1481 context names have special meanings, so @code{\new} cannot be
1485 @node Default contexts
1486 @subsection Default contexts
1488 Every top level music is interpreted by the @code{Score} context; in
1489 other words, you may think of @code{\score} working like
1493 \context Score @var{music}
1497 Music expressions inherit their context from the enclosing music
1498 expression. Hence, it is not necessary to explicitly specify
1499 @code{\context} for most expressions. In
1500 the following example, only the sequential expression has an explicit
1501 context. The notes contained therein inherit the @code{goUp} context
1502 from the enclosing music expression.
1504 @lilypond[verbatim,raggedright]
1505 \notes \context Voice = goUp { c'4 d' e' }
1509 Second, contexts are created automatically to be able to interpret the
1510 music expressions. Consider the following example:
1512 @lilypond[verbatim,raggedright]
1513 \score { \notes { c'4-( d' e'-) } }
1517 The sequential music is interpreted by the Score context initially,
1518 but when a note is encountered, contexts are setup to accept that
1519 note. In this case, a @code{Voice}, and @code{Staff}
1520 context are created. The rest of the sequential music is also
1521 interpreted with the same @code{Voice}, and
1522 @code{Staff} context, putting the notes on the same staff, in the same
1525 @node Context properties
1526 @subsection Context properties
1528 Contexts have properties. These properties are set from the @file{.ly}
1529 file using the following expression:
1530 @cindex context properties
1531 @cindex properties, context
1534 \set @var{contextname}.@var{propname} = @var{value}
1538 Sets the @var{propname} property of the context @var{contextname} to
1539 the specified Scheme expression @var{value}. Both @var{propname} and
1540 @var{contextname} are strings, which can often be written unquoted.
1543 Properties that are set in one context are inherited by all of the
1544 contained contexts. This means that a property valid for the
1545 @internalsref{Voice} context can be set in the @internalsref{Score} context
1546 (for example) and thus take effect in all @internalsref{Voice} contexts.
1548 Properties can be unset using the following statement.
1550 \unset @var{contextname}.@var{propname}
1553 @cindex properties, unsetting
1554 @cindex @code{\unset}
1557 This removes the definition of @var{propname} in @var{contextname}. If
1558 @var{propname} was not defined in @var{contextname} (but was inherited
1559 from a higher context), then this has no effect.
1561 If @var{contextname} is left out, then it defaults to the current
1562 ``bottom'' context: this is a context like @internalsref{Voice} that
1563 cannot contain any other contexts.
1566 @node Defining contexts
1567 @subsection Defining contexts
1569 @cindex context definition
1570 @cindex translator definition
1572 The most common way to create a new context definition is by extending
1573 an existing one. An existing context from the paper block is copied
1574 by referencing a context identifier:
1579 @var{context-identifier}
1585 Every predefined context has a standard identifier. For example, the
1586 @code{Staff} context can be referred to as @code{\StaffContext}.
1588 The context can then be modified by setting or changing properties,
1593 Stem \set #'thickness = #2.0
1594 defaultBarType = #"||"
1597 These assignments happen before interpretation starts, so a property
1598 command will override any predefined settings.
1604 It is not possible to collect multiple property assignments in a
1605 variable, and apply to one @code{\context} definition by
1606 referencing that variable.
1608 @node Changing contexts locally
1609 @subsection Changing contexts locally
1612 Extending an existing context can also be done locally. A piece of
1613 music can be interpreted in a changed context by using the following syntax
1617 @var{context modifications}
1621 These statements comes between @code{\new} or @code{\context} and the
1622 music to be interpreted. The @var{context modifications} property
1623 settings and @code{\remove}, @code{\consists} and @code{\consistsend}
1624 commands. The syntax is similar to the @code{\context} block.
1626 The following example shows how a staff is created with bigger spaces,
1627 and without a @code{Clef_engraver}.
1629 @lilypond[relative=1,fragment,verbatim]
1631 \new Staff { c4 es4 g2 }
1633 \override StaffSymbol #'staff-space = #(magstep 1.5)
1635 \remove "Clef_engraver"
1643 The command @code{\with} has no effect on contexts that already
1647 @node Engravers and performers
1648 @subsection Engravers and performers
1651 Each context is composed of a number of building blocks, or plug-ins
1652 called engravers. An engraver is a specialized C++ class that is
1653 compiled into the executable. Typically, an engraver is responsible
1654 for one function: the @code{Slur_engraver} creates only @code{Slur}
1655 objects, and the @code{Skip_event_swallow_translator} only swallows
1656 (silently gobbles) @code{SkipEvent}s.
1663 An existing context definition can be changed by adding or removing an
1664 engraver. The syntax for these operations is
1666 \consists @var{engravername}
1667 \remove @var{engravername}
1670 @cindex @code{\consists}
1671 @cindex @code{\remove}
1674 Here @var{engravername} is a string, the name of an engraver in the
1675 system. In the following example, the @code{Clef_engraver} is removed
1676 from the Staff context. The result is a staff without a clef, where
1677 the middle C is at its default position, the center line:
1679 @lilypond[verbatim,raggedright]
1687 \remove Clef_engraver
1693 A list of all engravers is in the internal documentation,
1694 see @internalsref{Engravers}.
1696 @node Defining new contexts
1697 @subsection Defining new contexts
1700 It is also possible to define new contexts from scratch. To do this,
1701 you must define give the new context a name. In the following
1702 example, a very simple Staff context is created: one that will put
1703 note heads on a staff symbol.
1707 \type "Engraver_group_engraver"
1710 \consists "Staff_symbol_engraver"
1711 \consists "Note_head_engraver"
1712 \consistsend "Axis_group_engraver"
1717 The argument of @code{\type} is the name for a special engraver that
1718 handles cooperation between simple engravers such as
1719 @code{Note_head_engraver} and @code{Staff_symbol_engraver}. This
1720 should always be @code{Engraver_group_engraver} (unless you are
1721 defining a Score context from scratch, in which case
1722 @code{Score_engraver} must be used).
1724 The complete list of context modifiers is the following:
1726 @item @code{\alias} @var{alternate-name}:
1727 This specifies a different name. In the above example,
1728 @code{\set Staff.X = Y} will also work on @code{SimpleStaff}s.
1730 @item @code{\consistsend} @var{engravername}:
1731 Analogous to @code{\consists}, but makes sure that
1732 @var{engravername} is always added to the end of the list of
1735 Engravers that group context objects into axis groups or alignments
1736 need to be at the end of the list. @code{\consistsend} insures that
1737 engravers stay at the end even if a user adds or removes engravers.
1739 @item @code{\accepts} @var{contextname}:
1740 This context can contains @var{contextname} contexts. The first
1741 @code{\accepts} is created as a default context when events (e.g. notes
1742 or rests) are encountered.
1744 @item @code{\denies}:
1745 The opposite of @code{\accepts}.
1747 @item @code{\name} @var{contextname}:
1748 This sets the type name of the context, e.g. @code{Staff},
1749 @code{Voice}. If the name is not specified, the translator will not
1758 @node Output details
1759 @section Output details
1761 The default output format is La@TeX{}, which should be run
1762 through La@TeX{}. Using the option @option{-f}
1763 (or @option{--format}) other output formats can be selected also, but
1764 none of them work reliably.
1766 Now the music is output system by system (a `system' consists of all
1767 staves belonging together). From @TeX{}'s point of view, a system is an
1768 @code{\hbox} which contains a lowered @code{\vbox} so that it is centered
1769 vertically on the baseline of the text. Between systems,
1770 @code{\interscoreline} is inserted vertically to have stretchable space.
1771 The horizontal dimension of the @code{\hbox} is given by the
1772 @code{linewidth} parameter from LilyPond's @code{\paper} block.
1774 After the last system LilyPond emits a stronger variant of
1775 @code{\interscoreline} only if the macro
1776 @code{\lilypondpaperlastpagefill} is not defined (flushing the systems
1777 to the top of the page). You can avoid that by setting the variable
1778 @code{lastpagefill} in LilyPond's @code{\paper} block.
1780 It is possible to fine-tune the vertical offset further by defining the
1781 macro @code{\lilypondscoreshift}:
1784 \def\lilypondscoreshift@{0.25\baselineskip@}
1788 where @code{\baselineskip} is the distance from one text line to the next.
1790 Here an example how to embed a small LilyPond file @code{foo.ly} into
1791 running La@TeX{} text without using the @code{lilypond-book} script
1792 (@pxref{lilypond-book manual}):
1795 \documentclass@{article@}
1797 \def\lilypondpaperlastpagefill@{@}
1799 \def\lilypondscoreshift@{0.25\baselineskip@}
1802 This is running text which includes an example music file
1808 The file @file{foo.tex} has been simply produced with
1814 The call to @code{\lineskip} assures that there is enough vertical space
1815 between the LilyPond box and the surrounding text lines.