@c -*-texinfo-*- @node Changing defaults @chapter Changing defaults The purpose of LilyPond's design is to provide the finest output quality as a default. Nevertheless, it may happen that you need to change this default layout. The layout is controlled through a large number of proverbial ``knobs and switches.'' This chapter does not list each and every knob. Rather, it outlines what groups of controls are available and explains how to lookup which knob to use for a certain effect. The controls available for tuning are described in a separate document, the @internalsref{Program reference} manual. That manual lists all different variables, functions and options available in LilyPond. It is written as a HTML document, which is available @uref{http://lilypond.org/doc/Documentation/user/out-www/lilypond-internals/,on-line}, but is also included with the LilyPond documentation package. There are three areas where the default settings may be changed: @itemize @bullet @item Output: changing the appearance of individual objects. For example, changing stem directions, or the location of subscripts. @item Context: changing aspects of the translation from music events to notation. For example, giving each staff a separate time signature. @item Global layout: changing the appearance of the spacing, line breaks and page dimensions. @end itemize Then, there are separate systems for typesetting text (like @emph{ritardando}) and selecting different fonts. This chapter also discusses these. Internally, LilyPond uses Scheme (a LISP dialect) to provide infrastructure. Overriding layout decisions in effect accesses the program internals, so it is necessary to learn a (very small) subset of Scheme. That is why this chapter starts with a short tutorial on entering numbers, lists, strings and symbols in Scheme. @menu * Scheme tutorial:: * File structure:: * Interpretation contexts:: * Tuning output:: * Fonts:: * Text markup:: * Global layout:: @end menu @node Scheme tutorial @section Scheme tutorial @cindex Scheme @cindex GUILE @cindex Scheme, in-line code @cindex accessing Scheme @cindex evaluating Scheme @cindex LISP LilyPond uses the Scheme programming language, both as part of the input syntax, and as internal mechanism to glue together modules of the program. This section is a very brief overview of entering data in Scheme.@footnote{If you want to know more about Scheme, see @uref{http://www.schemers.org}.} The most basic thing of a language is data: numbers, character strings, lists, etc. Here is a list of data types that are relevant to LilyPond input. @table @asis @item Booleans Boolean values are True or False. The Scheme for True is @code{#t} and False is @code{#f}. @item Numbers Numbers are entered in the standard fashion, @code{1} is the (integer) number one, while @code{-1.5} is a floating point number (a non-integer number). @item Strings Strings are enclosed in double quotes, @example "this is a string" @end example Strings may span several lines @example "this is a string" @end example Quotation marks and newlines can also be added with so-called escape sequences. The string @code{a said "b"} is entered as @example "a said \"b\"" @end example Newlines and backslashes are escaped with @code{\n} and @code{\\} respectively. @end table In a music file, snippets of Scheme code are introduced with the hash mark @code{#}. So, the previous examples translated in LilyPond are @example ##t ##f #1 #-1.5 #"this is a string" #"this is a string" @end example For the rest of this section, we will assume that the data is entered in a music file, so we add @code{#}s everywhere. Scheme can be used to do calculations. It uses @emph{prefix} syntax. Adding 1 and 2 is written as @code{(+ 1 2)} rather than the traditional 1+2. @lisp #(+ 1 2) @result{} #3 @end lisp The arrow @result{} shows that the result of evaluating @code{(+ 1 2)} is @code{3}. Calculations may be nested; the result of a function may be used for another calculation. @lisp #(+ 1 (* 3 4)) @result{} #(+ 1 12) @result{} #13 @end lisp These calculations are examples of evaluations; an expression like @code{(* 3 4)} is replaced by its value @code{12}. A similar thing happens with variables. After defining a variable @example twelve = #12 @end example variables can also be used in expressions, here @example twentyFour = #(* 2 twelve) @end example the number 24 is stored in the variable @code{twentyFour}. The @emph{name} of a variable is also an expression, similar to a number or a string. It is entered as @example #'twentyFour @end example The quote mark @code{'} prevents Scheme interpreter from substituting @code{24} for the @code{twentyFour}. Instead, we get the name @code{twentyFour}. This syntax will be used very frequently, since many of the layout tweaks involve assigning (Scheme) values to internal variables, for example @example \override Stem #'thickness = #2.6 @end example This instruction adjusts the appearance of stems. The value @code{2.6} is put into a the @code{thickness} variable of a @code{Stem} object. This makes stems almost twice as thick as their normal size. To distinguish between variables defined in input files (like @code{twentyFour} in the example above), and internal variables, we will call the latter ``properties.'' So, the stem object has a @code{thickness} property. Two-dimensional offsets (X and Y coordinates) as well as object sizes (intervals with a left and right point) are entered as @code{pairs}. A pair@footnote{In Scheme terminology, the pair is called @code{cons}, and its two elements are called car and cdr respectively.} is entered as @code{(first . second)} and, like symbols, they must be quoted, @example \override TextScript #'extra-offset = #'(1 . 2) @end example This assigns the pair (1, 2) to @code{extra-offset} variable of the TextScript object. This moves the object 1 staff space to the right, and 2 spaces up. The two elements of a pair may be arbitrary values, for example @example #'(1 . 2) #'(#t . #f) #'("blah-blah" . 3.14159265) @end example A list is entered by enclosing its elements in parentheses, and adding a quote. For example, @example #'(1 2 3) #'(1 2 "string" #f) @end example We have been using lists all along. A calculation, like @code{(+ 1 2)} is also a list (containing the symbol @code{+} and the numbers 1 and 2). Normally lists are interpreted as calculations, and the Scheme interpreter substitutes the outcome of the calculation. To enter a list, we stop evaluation. This is done by quoting the list with a quote @code{'} symbol. For calculations, do not use a quote. Inside a quoted list or pair, there is no need to quote anymore. The following is a pair of symbols, a list of symbols and a list of lists respectively, @example #'(stem . head) #'(staff clef key-signature) #'((1) (2)) @end example @node File structure @section File structure The following items may be present in a @file{.ly} file at toplevel @itemize @bullet @item An output definition, such as @code{\bookpaper}, @code{\midi} and @code{\paper}. Such a definition at toplevel changes the default settings for the block entered. @item An @code{\header} block. This sets the global header block. This is the block containing the definitions for book-wide settings, like composer, title, etc. @item An @code{\addquote} statement. See @ref{Quoting other voices} for more information. @item A @code{\score} block. This score will be collected with other toplevel scores, and combined as a single @code{\book}. This behavior can be changed by setting the variable @code{toplevel-score-handler} at toplevel. The default handler is defined in the init file @file{scm/lily.scm}. @item A @code{\book} block formats the block This behavior can be changed by setting the variable @code{toplevel-book-handler} at toplevel. The default handler is defined in the init file @file{scm/lily.scm}. @item A compound music expression, such as @example @{ c'4 d' e'2 @} @end example This will add the piece in a @code{\score}, and formats it into a single book together with all other toplevel @code{\score}s and music expressions. This behavior can be changed by setting the variable @code{toplevel-music-handler} at toplevel. The default handler is defined in the init file @file{scm/lily.scm}. @end itemize The following example shows three things which may be entered at toplevel @verbatim \paper { % movements are non-justified by default raggedright = ##t } \header { title = "Do-re-mi" } { c'4 d' e2 } @end verbatim At any point in a file, any of the following lexical instructions can be entered: @itemize @bullet @item @code{\version} @item @code{\include} @item @code{\encoding} @item @code{\renameinput} @end itemize @node Interpretation contexts @section Interpretation contexts When music is printed, a lot of notation elements must be added to the input, which is often bare bones. For example, compare the input and output of the following example: @lilypond[verbatim,relative=2,fragment] cis4 cis2. g4 @end lilypond The input is rather sparse, but in the output, bar lines, accidentals, clef, and time signature are added. LilyPond @emph{interprets} the input. During this step, the musical information is inspected in time order, similar to reading a score from left to right. While reading, the program remembers where measure boundaries are, and what pitches need explicit accidentals. This information can be presented on several levels. For example, the effect of an accidental is limited to a single stave, while a bar line must be synchronized across the entire score. Within LilyPond, these rules and bits of information are grouped in so-called Contexts. Examples of context are @context{Voice}, @context{Staff}, and @context{Score}. They are hierarchical, for example, a @context{Staff} can contain many @context{Voice}s, and a @context{Score} can contain many @context{Staff} contexts. Each context has the responsibility for enforcing some notation rules, creating some notation objects and maintaining the associated properties. So, the synchronization of bar lines is handled at @context{Score} context. The @context{Voice} may introduce an accidentals and then the @context{Staff} context maintains the rule to show or suppress the accidental for the remainder of the measure. For simple scores, contexts are created implicitly, and you need not be aware of them. For larger pieces, such as piano music, they must be created explicitly to make sure that you get as many staves as you need, and that they are in the correct order. For typesetting pieces with specialized notation, it can be useful to modify existing or define new contexts. Full description of all available contexts is in the program reference, see @ifhtml @internalsref{Contexts}. @end ifhtml @ifnothtml Translation @arrow{} Context. @end ifnothtml @c [TODO: describe propagation] @menu * Creating contexts:: * Changing context properties on the fly:: * Modifying context plug-ins:: * Layout tunings within contexts:: * Changing context default settings:: * Defining new contexts:: * Which properties to change:: @end menu @node Creating contexts @subsection Creating contexts For scores with only one voice and one staff, correct contexts are created automatically. For more complex scores, it is necessary to create them by hand. There are three commands which do this. The easiest command is @code{\new}, and it also the quickest to type. It is prepended to a music expression, for example @cindex @code{\new} @cindex new contexts @cindex Context, creating @example \new @var{type} @var{music expression} @end example @noindent where @var{type} is a context name (like @code{Staff} or @code{Voice}). This command creates a new context, and starts interpreting @var{music expression} with that. A practical application of @code{\new} is a score with many staves. Each part that should be on its own staff, is preceded with @code{\new Staff}. @lilypond[verbatim,relative=2,raggedright,fragment] << \new Staff { c4 c } \new Staff { d4 d } >> @end lilypond @cindex @code{\context} Like @code{\new}, the @code{\context} command also directs a music expression to a context object, but gives the context an extra name. The syntax is @example \context @var{type} = @var{id} @var{music} @end example This form will search for an existing context of type @var{type} called @var{id}. If that context does not exist yet, it is created. This is useful if the context is referred to later on. For example, when setting lyrics the melody is in a named context @example \context Voice = "@b{tenor}" @var{music} @end example @noindent so the texts can be properly aligned to its notes, @example \new Lyrics \lyricsto "@b{tenor}" @var{lyrics} @end example @noindent Another possibility is funneling two different music expressions into one context. In the following example, articulations and notes are entered separately, @verbatim music = { c4 c4 } arts = { s4-. s4-> } @end verbatim They are combined by sending both to the same @context{Voice} context, @verbatim << \new Staff \context Voice = "A" \music \context Voice = "A" \arts >> @end verbatim @lilypond[raggedright] music = { c4 c4 } arts = { s4-. s4-> } \relative c'' << \new Staff \context Voice = "A" \music \context Voice = "A" \arts >> @end lilypond @cindex @code{\context} @cindex creating contexts The third command for creating contexts is @example \context @var{type} @var{music} @end example @noindent This is similar to @code{\context} with @code{= @var{id}}, but matches any context of type @var{type}, regardless of its given name. This variant is used with music expressions that can be interpreted at several levels. For example, the @code{\applyoutput} command (see @ref{Running a function on all layout objects}). Without an explicit @code{\context}, it is usually is applied to @context{Voice} @example \applyoutput #@var{function} % apply to Voice @end example To have it interpreted at the @context{Score} or @context{Staff} level use these forms @example \context Score \applyoutput #@var{function} \context Staff \applyoutput #@var{function} @end example @node Changing context properties on the fly @subsection Changing context properties on the fly @cindex properties @cindex @code{\set} @cindex changing properties Each context can have different @emph{properties}, variables contained in that context. They can be changed during the interpretation step. This is achieved by inserting the @code{\set} command in the music, @quotation @code{\set } @var{context}@code{.}@var{prop}@code{ = #}@var{value} @end quotation For example, @lilypond[verbatim,relative=2,fragment] R1*2 \set Score.skipBars = ##t R1*2 @end lilypond This command skips measures that have no notes. The result is that multi rests are condensed. The value assigned is a Scheme object. In this case, it is @code{#t}, the boolean True value. If the @var{context} argument is left out, then the current bottom-most context (typically @context{ChordNames}, @context{Voice}, or @context{Lyrics}) is used. In this example, @lilypond[verbatim,relative=2,fragment] c8 c c c \set autoBeaming = ##f c8 c c c @end lilypond @noindent the @var{context} argument to @code{\set} is left out, and the current @internalsref{Voice} is used. Contexts are hierarchical, so if a bigger context was specified, for example @context{Staff}, then the change would also apply to all @context{Voice}s in the current stave. The change is applied `on-the-fly', during the music, so that the setting only affects the second group of eighth notes. @cindex @code{\unset} There is also an @code{\unset} command, @quotation @code{\unset }@var{context}@code{.}@var{prop} @end quotation @noindent which removes the definition of @var{prop}. This command removes the definition only if it is set in @var{context}. In @example \set Staff.autoBeaming = ##f \unset Voice.autoBeaming @end example @noindent the current @context{Voice} does not have the property, and the definition at @context{Staff} level remains intact. Like @code{\set}, the @var{context} argument does not have to be specified for a bottom context. Settings that should only apply to a single time-step can be entered easily with @code{\once}, for example in @lilypond[verbatim,relative=2,fragment] c4 \once \set fontSize = #4.7 c4 c4 @end lilypond the property @code{fontSize} is unset automatically after the second note. A full description of all available context properties is in the program reference, see @ifhtml @internalsref{Tunable-context-properties}. @end ifhtml @ifnothtml Translation @arrow{} Tunable context properties. @end ifnothtml @node Modifying context plug-ins @subsection Modifying context plug-ins Notation contexts (like Score and Staff) not only store properties, they also contain plug-ins, called ``engravers'' that create notation elements. For example, the Voice context contains a @code{Note_head_engraver} and the Staff context contains a @code{Key_signature_engraver}. For a full a description of each plug-in, see @ifhtml @internalsref{Engravers}. @end ifhtml @ifnothtml Program reference @arrow Translation @arrow{} Engravers. @end ifnothtml Every context described in @ifhtml @internalsref{Contexts} @end ifhtml @ifnothtml Program reference @arrow Translation @arrow{} Context. @end ifnothtml lists the engravers used for that context. It can be useful to shuffle around these plug-ins. This is done by starting a new context, with @code{\new} or @code{\context}, and modifying it like this, @example \new @var{context} \with @{ \consists @dots{} \consists @dots{} \remove @dots{} \remove @dots{} @emph{etc.} @} @var{..music..} @end example where the @dots{} should be the name of an engraver. Here is a simple example which removes @code{Time_signature_engraver} and @code{Clef_engraver} from a @code{Staff} context, @lilypond[relative=1, verbatim,fragment] << \new Staff { f2 g } \new Staff \with { \remove "Time_signature_engraver" \remove "Clef_engraver" } { f2 g2 } >> @end lilypond In the second stave there are no time signature or clef symbols. This is a rather crude method of making objects disappear since it will affect the entire staff. The spacing will be adversely influenced too. A more sophisticated methods of blanking objects is shown in @ref{Common tweaks}. The next example shows a practical application. Bar lines and time signatures are normally synchronized across the score. This is done by the @code{Timing_engraver}. This plug-in keeps an administration of time signature, location within the measure, etc. By moving the @code{Timing_engraver} engraver from Score to Staff context, we can have a score where each staff has its own time signature. @cindex polymetric scores @lilypond[relative=1,raggedright,verbatim,fragment] \new Score \with { \remove "Timing_engraver" } << \new Staff \with { \consists "Timing_engraver" } { \time 3/4 c4 c c c c c } \new Staff \with { \consists "Timing_engraver" } { \time 2/4 c4 c c c c c } >> @end lilypond @node Layout tunings within contexts @subsection Layout tunings within contexts Each context is responsible for creating certain types of graphical objects. The settings used for printing these objects are also stored by context. By changing these settings, the appearance of objects can be altered. The syntax for this is @example \override @var{context}.@var{name}@code{ #'}@var{property} = #@var{value} @end example Here @var{name} is the name of a graphical object, like @code{Stem} or @code{NoteHead}, and @var{property} is an internal variable of the formatting system (`grob property' or `layout property'). The latter is a symbol, so it must be quoted. The subsection @ref{Constructing a tweak} explains what to fill in for @var{name}, @var{property}, and @var{value}. Here we only discuss functionality of this command. The command @verbatim \override Staff.Stem #'thickness = #4.0 @end verbatim @noindent makes stems thicker (the default is 1.3, with staff line thickness as a unit). Since the command specifies @context{Staff} as context, it only applies to the current staff. Other staves will keep their normal appearance. Here we see the command in action: @lilypond[verbatim,relative=2,fragment] c4 \override Staff.Stem #'thickness = #4.0 c4 c4 c4 @end lilypond The @code{\override} command is executed during the interpreting phase, and changes the definition of the @code{Stem} within @context{Staff}. After the command all stems are thickened. Analogous to @code{\set}, the @var{context} argument may be left out, causing it to default to @context{Voice}, and adding @code{\once} applies the change during one timestep only @lilypond[fragment,verbatim,relative=2] c4 \once \override Stem #'thickness = #4.0 c4 c4 @end lilypond The @code{\override} must be done before the object is started. Therefore, when altering @emph{Spanner} objects, like slurs or beams, the @code{\override} command must be executed at the moment when the object is created. In this example, @lilypond[fragment,verbatim,relative=2] \override Slur #'thickness = #3.0 c8[( c \override Beam #'thickness = #0.6 c8 c]) @end lilypond @noindent the slur is fatter and the beam is not. This is because the command for @code{Beam} comes after the Beam is started. Therefore it has no effect. Analogous to @code{\unset}, the @code{\revert} command for a context undoes a @code{\override} command; like with @code{\unset}, it only affects settings that were made in the same context. In other words, the @code{\revert} in the next example does not do anything. @verbatim \override Voice.Stem #'thickness = #4.0 \revert Staff.Stem #'thickness @end verbatim @seealso Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty}, @internalsref{PropertySet}, @internalsref{All-backend-properties}, and @internalsref{All-layout-objects}. @refbugs The back-end is not very strict in type-checking object properties. Cyclic references in Scheme values for properties can cause hangs or crashes, or both. @node Changing context default settings @subsection Changing context default settings The adjustments of the previous chapters can also be entered separate from the music, in the @code{\paper} block, @example \paper @{ @dots{} \context @{ \Staff \set fontSize = #-2 \override Stem #'thickness \remove "Time_signature_engraver" @} @} @end example Here @example \Staff @end example @noindent takes the existing definition @context{Staff} from the identifier @code{Staff}. This works analogously to other contexts. The statements @example \set fontSize = #-2 \override Stem #'thickness \remove "Time_signature_engraver" @end example @noindent affect all staves in the score. The @code{\set} keyword is optional within the @code{\paper} block, so @example fontSize = #-2 @end example @noindent will also work. @refbugs It is not possible to collect changes in a variable, and apply them to one @code{\context} definition by referring to that variable. @node Defining new contexts @subsection Defining new contexts Specific contexts, like @context{Staff} and @code{Voice}, are made of simple building blocks, and it is possible to compose engraver plug-ins in different combinations, thereby creating new types of contexts. The next example shows how to build a different type of @context{Voice} context from scratch. It will be similar to @code{Voice}, but print centered slash noteheads only. It can be used to indicate improvisation in Jazz pieces, @lilypond[raggedright] \paper { \context { \name ImproVoice \type "Engraver_group_engraver" \consists "Note_heads_engraver" \consists "Text_engraver" \consists Pitch_squash_engraver squashedPosition = #0 \override NoteHead #'style = #'slash \override Stem #'transparent = ##t \alias Voice } \context { \Staff \accepts "ImproVoice" }} \relative c'' { a4 d8 bes8 \new ImproVoice { c4^"ad lib" c c4 c^"undress" c_"while playing :)" c } a1 } @end lilypond These settings are again done within a @code{\context} block inside a @code{\paper} block, @example \paper @{ \context @{ @dots{} @} @} @end example In the following discussion, the example input shown should go on the @dots{} in the previous fragment. First, name the context gets a name. Instead of @context{Voice} it will be called @context{ImproVoice}, @verbatim \name ImproVoice @end verbatim Since it is similar to the @context{Voice}, we want commands that work on (existing) @context{Voice}s to remain working. This is achieved by giving the new context an alias @context{Voice}, @verbatim \alias Voice @end verbatim The context will print notes, and instructive texts @verbatim \consists Note_heads_engraver \consists Text_engraver @end verbatim but only on the center line, @verbatim \consists Pitch_squash_engraver squashedPosition = #0 @end verbatim The @internalsref{Pitch_squash_engraver} modifies note heads (created by @internalsref{Note_heads_engraver}) and sets their vertical position to the value of @code{squashedPosition}, in this case @code{0}, the center line. The notes look like a slash, without a stem, @verbatim \override NoteHead #'style = #'slash \override Stem #'transparent = ##t @end verbatim All these plug-ins have to cooperate, and this is achieved with a special plug-in, which must be marked with the keyword @code{\type}. This should always be @internalsref{Engraver_group_engraver}, @example \type "Engraver_group_engraver" @end example Putting together, we get @verbatim \context { \name ImproVoice \type "Engraver_group_engraver" \consists "Note_heads_engraver" \consists "Text_script_engraver" \consists Pitch_squash_engraver squashedPosition = #0 \override NoteHead #'style = #'slash \override Stem #'transparent = ##t \alias Voice } @end verbatim Contexts form hierarchies. We want to hang the @context{ImproVoice} under @context{Staff}, just like normal @code{Voice}s. Therefore, we modify the @code{Staff} definition with the @code{\accepts} command,@footnote{The opposite of @code{\accepts} is @code{\denies}, which is sometimes when reusing existing context definitions. } @verbatim \context { \Staff \accepts ImproVoice } @end verbatim Putting both into a @code{\paper} block, like @example \paper @{ \context @{ \name ImproVoice @dots{} @} \context @{ \Staff \accepts "ImproVoice" @} @} @end example Then the output at the start of this subsection can be entered as @verbatim \relative c'' { a4 d8 bes8 \new ImproVoice { c4^"ad lib" c c4 c^"undress" c c_"while playing :)" } a1 } @end verbatim @node Which properties to change @subsection Which properties to change There are many different properties. Not all of them are listed in this manual. However, the program reference lists them all in the section @internalsref{Tunable-context-properties}, and most properties are demonstrated in one of the @ifhtml @uref{../../../../input/test/out-www/collated-files.html,tips-and-tricks} @end ifhtml @ifnothtml tips-and-tricks @end ifnothtml examples. @node Tuning output @section Tuning output In the previous section, we have already touched on a command that changes layout details, the @code{\override} command. In this section, we will look at in more detail how to use the command in practice. First, we will give a a few versatile commands, which are sufficient for many situations. The next section will discuss general use of @code{\override}. @ignore There are situations where default layout decisions are not sufficient. In this section we discuss ways to override these defaults. Formatting is internally done by manipulating so called objects (graphic objects). Each object carries with it a set of properties (object or layout properties) specific to the object. For example, a stem object has properties that specify its direction, length, and thickness. The most direct way of tuning the output is to alter the values of these properties. There are two ways of doing that: First, you can temporarily change the definition of one type of object, thus affecting a whole set of objects. Second, you can select one specific object, and set a layout property in that object. Do not confuse layout properties with translation properties. Translation properties always use a mixed caps style naming, and are manipulated using @code{\set} and @code{\unset}: @example \set Context.propertyName = @var{value} @end example Layout properties are use Scheme style variable naming, i.e. lower case words separated with dashes. They are symbols, and should always be quoted using @code{#'}. For example, this could be an imaginary layout property name: @example #'layout-property-name @end example @end ignore @menu * Common tweaks:: * Constructing a tweak:: * Navigating the program reference:: * Layout interfaces:: * Determining the grob property:: @end menu @node Common tweaks @subsection Common tweaks Some overrides are so common that predefined commands are provided as a short-cut, for example, @code{\slurUp} and @code{\stemDown}. These commands are described in @ifhtml the @end ifhtml @ref{Notation manual}, under the sections for slurs and stems respectively. The exact tuning possibilities for each type of layout object are documented in the program reference of the respective object. However, many layout objects share properties, which can be used to apply generic tweaks. We mention a few of these: @itemize @bullet @item The @code{extra-offset} property, which @cindex @code{extra-offset} has a pair of numbers as value, moves around objects in the printout. The first number controls left-right movement; a positive number will move the object to the right. The second number controls up-down movement; a positive number will move it higher. The units of these offsets are staff-spaces. The @code{extra-offset} property is a low-level feature: the formatting engine is completely oblivious to these offsets. In the following example, the second fingering is moved a little to the left, and 1.8 staff space downwards: @cindex setting object properties @lilypond[fragment,relative=1,verbatim] \stemUp f-5 \once \override Fingering #'extra-offset = #'(-0.3 . -1.8) f-5 @end lilypond @item Setting the @code{transparent} property will cause an object to be printed in `invisible ink': the object is not printed, but all its other behavior is retained. The object still takes up space, it takes part in collisions, and slurs, and ties and beams can be attached to it. @cindex transparent objects @cindex removing objects @cindex hiding objects @cindex invisible objects The following example demonstrates how to connect different voices using ties. Normally, ties only connect two notes in the same voice. By introducing a tie in a different voice, @lilypond[fragment,relative=2] << { b8~ b8\noBeam } \\ { b[ g8] } >> @end lilypond @noindent and blanking a stem in that voice, the tie appears to cross voices: @lilypond[fragment,relative=2,verbatim] << { \once \override Stem #'transparent = ##t b8~ b8\noBeam } \\ { b[ g8] } >> @end lilypond @item The @code{padding} property for objects with @cindex @code{padding} @code{side-position-interface} can be set to increase distance between symbols that are printed above or below notes. We only give an example; a more elaborate explanation is in @ref{Constructing a tweak}: @lilypond[fragment,relative=1,verbatim] c2\fermata \override Script #'padding = #3 b2\fermata @end lilypond @end itemize More specific overrides are also possible. The next section discusses in depth how to figure out these statements for yourself. @node Constructing a tweak @subsection Constructing a tweak The general procedure of changing output, that is, entering a command like @example \override Voice.Stem #'thickness = #3.0 @end example @noindent means that we have to determine these bits of information: @itemize @item the context: here @context{Voice}. @item the layout object: here @code{Stem}. @item the layout property: here @code{thickness} @item a sensible value: here @code{3.0} @end itemize @cindex internal documentation @cindex finding graphical objects @cindex graphical object descriptions @cindex tweaking @cindex @code{\override} @cindex @code{\set} @cindex internal documentation We demonstrate how to glean this information from the notation manual and the program reference. The program reference is a set of HTML pages, which is part of the documentation package. On Unix systems, it is typically in @file{/usr/share/doc/lilypond}. If you have them, it is best to bookmark them in your webbrowser, because you will need them. They are also available on the web: go to the @uref{http://lilypond.org,LilyPond website}, click ``Documentation'', select the correct version, and then click ``Program reference.'' If you have them, use the local HTML files. They will load faster, and they are exactly matched to LilyPond version installed. @node Navigating the program reference @subsection Navigating the program reference Suppose we want to move the fingering indication in the fragment below: @lilypond[fragment,relative=2,verbatim] c-2 \stemUp f @end lilypond If you visit the documentation of @code{Fingering} (in @ref{Fingering instructions}), you will notice that there is written: @quotation @seealso Program reference: @internalsref{FingerEvent} and @internalsref{Fingering}. @end quotation This fragments points to two parts of the program reference: a page on @code{FingerEvent} and on @code{Fingering}. The page on @code{FingerEvent} describes the properties of the music expression for the input @code{-2}. The page contains many links forward. For example, it says @quotation Accepted by: @internalsref{Fingering_engraver}, @end quotation @noindent That link brings us to the documentation for the Engraver, the plug-in, which says @quotation This engraver creates the following layout objects: @internalsref{Fingering}. @end quotation In other words, once the @code{FingerEvent}s are interpreted, the @code{Fingering_engraver} plug-in will process them. The @code{Fingering_engraver} is also listed to create @internalsref{Fingering} objects, Lo and behold, that is also the second bit of information listed under @b{See also} in the Notation manual. By clicking around in the program reference, we can follow the flow of information within the program, either forward (like we did here), or backwards, following links like this: @itemize @bullet @item @internalsref{Fingering}: @internalsref{Fingering} objects are created by: @b{@internalsref{Fingering_engraver}} @item @internalsref{Fingering_engraver}: Music types accepted: @b{@internalsref{fingering-event}} @item @internalsref{fingering-event}: Music event type @code{fingering-event} is in Music objects of type @b{@internalsref{FingerEvent}} @end itemize This path goes against the flow of information in the program: it starts from the output, and ends at the input event. The program reference can also be browsed like a normal document. It contains a chapter on @ifhtml @internalsref{Music-definitions}, @end ifhtml @ifnothtml Music definitions @end ifnothtml on @internalsref{Translation}, and the @internalsref{Backend}. Every chapter lists all the definitions used, and all properties that may be tuned. @node Layout interfaces @subsection Layout interfaces @internalsref{Fingering} is a layout object. Such an object is a symbol within the score. It has properties, which store numbers (like thicknesses and directions), but also pointers to related objects. A layout object is also called @emph{grob}, @cindex grob which is short for Graphical Object. The page for @code{Fingering} lists the definitions for the @code{Fingering} object. For example, the page says @quotation @code{padding} (dimension, in staff space): @code{0.6} @end quotation which means that the number will be kept at a distance of at least 0.6 of the note head. Each layout object may have several functions as a notational or typographical element. For example, the Fingering object has the following aspects @itemize @bullet @item Its size is independent of the horizontal spacing, unlike slurs or beams @item It is a piece of text. Granted, it's usually a very short text. @item That piece of text is typeset with a font, unlike slurs or beams. @item Horizontally, the center of the symbol should be aligned to the center of the notehead @item Vertically, the symbol is placed next to the note and the staff. @item The vertical position is also coordinated with other super and subscript symbols @end itemize Each of these aspects is captured in a so-called @emph{interface}, which are listed on the @internalsref{Fingering} page at the bottom @quotation This object supports the following interfaces: @internalsref{item-interface}, @internalsref{self-alignment-interface}, @internalsref{side-position-interface}, @internalsref{text-interface}, @internalsref{text-script-interface}, @internalsref{font-interface}, @internalsref{finger-interface}, and @internalsref{grob-interface}. @end quotation Clicking any of the links will take you to the page of the respective object interface. Each interface has a number of properties. Some of them are not user-serviceable (``Internal properties''), but others are. We have been talking of `the' @code{Fingering} object, but actually it does not amount to much. The initialization file @file{scm/define-grobs.scm} shows the soul of the `object', @verbatim (Fingering . ( (print-function . ,Text_item::print) (padding . 0.6) (staff-padding . 0.6) (self-alignment-X . 0) (self-alignment-Y . 0) (script-priority . 100) (font-encoding . number) (font-size . -5) (meta . ((interfaces . (finger-interface font-interface text-script-interface text-interface side-position-interface self-alignment-interface item-interface)))) )) @end verbatim as you can see, @code{Fingering} is nothing more than a bunch of variable settings, and the webpage is directly generated from this definition. @node Determining the grob property @subsection Determining the grob property Recall that we wanted to change the position of the @b{2} in @lilypond[fragment,relative=2,verbatim] c-2 \stemUp f @end lilypond Since the @b{2} is vertically positioned next to its note, we have to meddle with the interface associated with this positioning. This is done using @code{side-position-interface}. The page for this interface says @quotation @code{side-position-interface} Position a victim object (this one) next to other objects (the support). The property @code{direction} signifies where to put the victim object relative to the support (left or right, up or down?) @end quotation @cindex padding @noindent below this description, the variable @code{padding} is described as @quotation @table @code @item padding (dimension, in staff space) add this much extra space between objects that are next to each other. @end table @end quotation By increasing the value of @code{padding}, we can move away the fingering. The following command inserts 3 staff spaces of white between the note and the fingering: @example \once \override Fingering #'padding = #3 @end example Inserting this command before the Fingering object is created, i.e. before @code{c2}, yields the following result: @lilypond[relative=2,fragment,verbatim] \once \override Fingering #'padding = #3 c-2 \stemUp f @end lilypond In this case, the context for this tweak is @context{Voice}, which does not have to be specified for @code{\override}. This fact can also be deduced from the program reference, for the page for the @internalsref{Fingering_engraver} plug-in says @quotation Fingering_engraver is part of contexts: @dots{} @b{@internalsref{Voice}} @end quotation @node Fonts @section Fonts @menu * Selecting font sizes:: * Font selection:: @end menu @node Selecting font sizes @subsection Selecting font sizes The most common thing to change about the appearance of fonts is their size. The font size of any context can be easily changed by setting the @code{fontSize} property for that context. Its value is a number: negative numbers make the font smaller, positive numbers larger. An example is given below: @c @lilypond[fragment,relative=1,verbatim] c4 c4 \set fontSize = #-3 f4 g4 @end lilypond This command will set @code{font-size} (see below) in all layout objects in the current context. It does not change the size of variable symbols, such as beams or slurs. The font size is set by modifying the @code{font-size} property. Its value is a number indicating the size relative to the standard size. Each step up is an increase of approximately 12% of the font size. Six steps is exactly a factor two. The Scheme function @code{magstep} converts a @code{font-size} number to a scaling factor. LilyPond has fonts in different design sizes: the music fonts for smaller sizes are chubbier, while the text fonts are relatively wider. Font size changes are achieved by scaling the design size that is closest to the desired size. The @code{font-size} mechanism does not work for fonts selected through @code{font-name}. These may be scaled with @code{font-magnification}. One of the uses of @code{fontSize} is to get smaller symbols for cue notes. An elaborate example of those is in @inputfileref{input/test,cue-notes.ly}. @cindex cue notes @cindex @code{font-style} @refcommands The following commands set @code{fontSize} for the current voice: @cindex @code{\tiny} @code{\tiny}, @cindex @code{\small} @code{\small}, @cindex @code{\normalsize} @code{\normalsize}. @cindex magnification @cindex cue notes @node Font selection @subsection Font selection Font selection for the standard fonts, @TeX{}'s Computer Modern fonts, can also be adjusted with a more fine-grained mechanism. By setting the object properties described below, you can select a different font; all three mechanisms work for every object that supports @code{font-interface}: @itemize @bullet @item @code{font-encoding} is a symbol that sets layout of the glyphs. Choices include @code{ec} for @TeX{} EC font encoding, @code{fetaBraces} (for piano staff braces), @code{fetaMusic} (the standard music font, including ancient glyphs), @code{fetaDynamic} (for dynamic signs) and @code{fetaNumber} for the number font. @item @code{font-family} is a symbol indicating the general class of the typeface. Supported are @code{roman} (Computer Modern), @code{sans}, and @code{typewriter}. @item @code{font-shape} is a symbol indicating the shape of the font, there are typically several font shapes available for each font family. Choices are @code{italic}, @code{caps}, and @code{upright}. @item @code{font-series} is a symbol indicating the series of the font. There are typically several font series for each font family and shape. Choices are @code{medium} and @code{bold}. @end itemize Fonts selected in the way sketched above come from a predefined style sheet. The font used for printing a object can be selected by setting @code{font-name}, e.g. @example \override Staff.TimeSignature #'font-name = #"cmr17" @end example @noindent Any font can be used, as long as it is available to @TeX{}. Possible fonts include foreign fonts or fonts that do not belong to the Computer Modern font family. The size of fonts selected in this way can be changed with the @code{font-magnification} property. For example, @code{2.0} blows up all letters by a factor 2 in both directions. @cindex font size @cindex font magnification @seealso Init files: @file{ly/declarations-init.ly} contains hints how new fonts may be added to LilyPond. @refbugs No style sheet is provided for other fonts besides the @TeX{} Computer Modern family. @cindex font selection @cindex font magnification @cindex @code{font-interface} @node Text markup @section Text markup @cindex text markup @cindex markup text @cindex typeset text LilyPond has an internal mechanism to typeset texts. You can access it with the keyword @code{\markup}. Within markup mode, you can enter texts similar to lyrics: simply enter them, surrounded by spaces: @cindex markup @lilypond[verbatim,fragment,relative=1] c1^\markup { hello } c1_\markup { hi there } c1^\markup { hi \bold there, is \italic anyone home? } @end lilypond @cindex font switching The markup in the example demonstrates font switching commands. The command @code{\bold} and @code{\italic} apply to the first following word only; enclose a set of texts with braces to apply a command to more words: @example \markup @{ \bold @{ hi there @} @} @end example @noindent For clarity, you can also do this for single arguments, e.g. @verbatim \markup { is \italic { anyone } home } @end verbatim @cindex font size, texts In markup mode you can compose expressions, similar to mathematical expressions, XML documents, and music expressions. The braces group notes into horizontal lines. Other types of lists also exist: you can stack expressions grouped with @code{<} and @code{>} vertically with the command @code{\column}. Similarly, @code{\center-align} aligns texts by their center lines: @lilypond[verbatim,fragment,relative=1] c1^\markup { \column < a bbbb c > } c1^\markup { \center-align < a bbbb c > } c1^\markup { \line < a b c > } @end lilypond Markups can be stored in variables, and these variables may be attached to notes, like @verbatim allegro = \markup { \bold \large { Allegro } } { a^\allegro b c d } @end verbatim Some objects have alignment procedures of their own, which cancel out any effects of alignments applied to their markup arguments as a whole. For example, the @internalsref{RehearsalMark} is horizontally centered, so using @code{\mark \markup @{ \left-align .. @}} has no effect. Similarly, for moving whole texts over notes with @code{\raise}, use the following trick: @example "" \raise #0.5 raised @end example The text @code{raised} is now raised relative to the empty string @code{""} which is not visible. Alternatively, complete objects can be moved with layout properties such as @code{padding} and @code{extra-offset}. @seealso Init files: @file{scm/new-markup.scm}. @refbugs Text layout is ultimately done by @TeX{}, which does kerning of letters. LilyPond does not account for kerning, so texts will be spaced slightly too wide. Syntax errors for markup mode are confusing. Markup texts cannot be used in the titling of the @code{\header} field. Titles are made by La@TeX{}, so La@TeX{} commands should be used for formatting. @menu * Text encoding:: * Overview of text markup commands:: @end menu @node Text encoding @subsection Text encoding Texts can be entered in different encodings. The encoding of the file can be set with @code{\encoding}. @example \encoding "latin1" @end example This command may be placed anywhere in the input file. The current encoding is passed as an extra argument to @code{\markup} commands. If no @code{\encoding} has been specified, then the encoding is taken from the @code{\paper} block (or @code{\bookpaper}, if @code{\paper} does not specify encoding). The variable @code{inputencoding} may be set to a string or symbol specifying the encoding, eg. @verbatim \paper { inputencoding = "latin1" } @end verbatim There is a special encoding, called @code{TeX}. This encoding does not reencode text for the font used. Rather, it tries to guess the width of @TeX{} commands, such as @code{\"}. Strings encoded with @code{TeX} are passed to the output back-end verbatim. @cindex encoding @cindex @code{\encoding} @cindex inputencoding @cindex @TeX{} commands in strings @node Overview of text markup commands @subsection Overview of text markup commands @include markup-commands.tely @node Global layout @section Global layout The global layout determined by three factors: the page layout, the line breaks, and the spacing. These all influence each other. The choice of spacing determines how densely each system of music is set, which influences where line breaks are chosen, and thus ultimately how many pages a piece of music takes. This section explains how to tune the algorithm for spacing. Globally spoken, this procedure happens in three steps: first, flexible distances (``springs'') are chosen, based on durations. All possible line breaking combination are tried, and the one with the best results --- a layout that has uniform density and requires as little stretching or cramping as possible --- is chosen. After spacing and linebreaking, the systems are distributed across pages, taking into account the size of the page, and the size of the titles. @menu * Setting global staff size:: * Vertical spacing:: * Horizontal spacing:: * Line breaking:: * Line length and line breaking:: * Titling:: * Page breaking:: * Paper size:: * Page layout:: @end menu @node Setting global staff size @subsection Setting global staff size @cindex font size, setting @cindex staff size, setting @cindex @code{paper} file The Feta font provides musical symbols at eight different sizes. Each font is tuned for a different staff size: at a smaller size the font becomes heavier, to match the relatively heavier staff lines. The recommended font sizes are listed in the following table: @multitable @columnfractions .25 .25 .25 .25 @item @b{font name} @tab @b{staff height (pt)} @tab @b{staff height (mm)} @tab @b{use} @item feta11 @tab 11.22 @tab 3.9 @tab pocket scores @item feta13 @tab 12.60 @tab 4.4 @tab @item feta14 @tab 14.14 @tab 5.0 @tab @item feta16 @tab 15.87 @tab 5.6 @tab @item feta18 @tab 17.82 @tab 6.3 @tab song books @item feta20 @tab 17.82 @tab 7.0 @tab standard parts @item feta23 @tab 22.45 @tab 7.9 @tab @item feta26 @tab 25.2 @tab 8.9 @tab @c modern rental material ? @end multitable These fonts are available in any sizes. The context property @code{fontSize} and the layout property @code{staff-space} (in @internalsref{StaffSymbol}) can be used to tune size for individual staves. The size of individual staves are relative to the global size, which can be set in the following manner: @example #(set-global-staff-size 14) @end example This sets the global default size to 14pt staff height, and scales all fonts accordingly. @seealso This manual: @ref{Selecting font sizes}. @menu * Vertical spacing:: * Horizontal spacing:: * Line breaking:: * Page layout:: @end menu @node Vertical spacing @subsection Vertical spacing @cindex vertical spacing @cindex distance between staves @cindex staff distance @cindex between staves, distance @cindex staves per page @cindex space between staves The height of each system is determined automatically by LilyPond, to keep systems from bumping into each other, some minimum distances are set. By changing these, you can put staves closer together, and thus put more systems onto one page. Normally staves are stacked vertically. To make staves maintain a distance, their vertical size is padded. This is done with the property @code{minimumVerticalExtent}. It takes a pair of numbers, so if you want to make it smaller from its, then you could set @example \set Staff.minimumVerticalExtent = #'(-4 . 4) @end example This sets the vertical size of the current staff to 4 staff spaces on either side of the center staff line. The argument of @code{minimumVerticalExtent} is interpreted as an interval, where the center line is the 0, so the first number is generally negative. The staff can be made larger at the bottom by setting it to @code{(-6 . 4)}. The piano staves are handled a little differently: to make cross-staff beaming work correctly, it is necessary that the distance between staves is fixed beforehand. This is also done with a @internalsref{VerticalAlignment} object, created in @internalsref{PianoStaff}. In this object the distance between the staves is fixed by setting @code{forced-distance}. If you want to override this, use a @code{\context} block as follows: @example \paper @{ \context @{ \PianoStaff \override VerticalAlignment #'forced-distance = #9 @} @dots{} @} @end example This would bring the staves together at a distance of 9 staff spaces, measured from the center line of each staff. @seealso Internals: Vertical alignment of staves is handled by the @internalsref{VerticalAlignment} object. @node Horizontal spacing @subsection Horizontal Spacing The spacing engine translates differences in durations into stretchable distances (``springs'') of differing lengths. Longer durations get more space, shorter durations get less. The shortest durations get a fixed amount of space (which is controlled by @code{shortest-duration-space} in the @internalsref{SpacingSpanner} object). The longer the duration, the more space it gets: doubling a duration adds a fixed amount (this amount is controlled by @code{spacing-increment}) of space to the note. For example, the following piece contains lots of half, quarter, and 8th notes, the eighth note is followed by 1 note head width (NHW). The quarter note is followed by 2 NHW, the half by 3 NHW, etc. @lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8 c8 c4 c4 c4 @end lilypond Normally, @code{spacing-increment} is set to 1.2, which is the width of a note head, and @code{shortest-duration-space} is set to 2.0, meaning that the shortest note gets 2 NHW of space. For normal notes, this space is always counted from the left edge of the symbol, so the shortest notes are generally followed by one NHW of space. If one would follow the above procedure exactly, then adding a single 32th note to a score that uses 8th and 16th notes, would widen up the entire score a lot. The shortest note is no longer a 16th, but a 32nd, thus adding 1 NHW to every note. To prevent this, the shortest duration for spacing is not the shortest note in the score, but the most commonly found shortest note. Notes that are even shorter this are followed by a space that is proportional to their duration relative to the common shortest note. So if we were to add only a few 16th notes to the example above, they would be followed by half a NHW: @lilypond[fragment,verbatim,relative=2] c2 c4. c8 c4. c16[ c] c4. c8 c8 c8 c4 c4 c4 @end lilypond The most common shortest duration is determined as follows: in every measure, the shortest duration is determined. The most common short duration, is taken as the basis for the spacing, with the stipulation that this shortest duration should always be equal to or shorter than 1/8th note. The shortest duration is printed when you run lilypond with @code{--verbose}. These durations may also be customized. If you set the @code{common-shortest-duration} in @internalsref{SpacingSpanner}, then this sets the base duration for spacing. The maximum duration for this base (normally 1/8th), is set through @code{base-shortest-duration}. @cindex @code{common-shortest-duration} @cindex @code{base-shortest-duration} @cindex @code{stem-spacing-correction} @cindex @code{spacing} In the Introduction it was explained that stem directions influence spacing. This is controlled with @code{stem-spacing-correction} property in @internalsref{NoteSpacing}, which are generated for every @internalsref{Voice} context. The @code{StaffSpacing} object (generated at @internalsref{Staff} context) contains the same property for controlling the stem/bar line spacing. The following example shows these corrections, once with default settings, and once with exaggerated corrections: @lilypond[raggedright] { c'4 e''4 e'4 b'4 | b'4 e''4 b'4 e''4| \override Staff.NoteSpacing #'stem-spacing-correction = #1.5 \override Staff.StaffSpacing #'stem-spacing-correction = #1.5 c'4 e''4 e'4 b'4 | b'4 e''4 b'4 e''4| } @end lilypond @cindex SpacingSpanner, overriding properties Properties of the @internalsref{SpacingSpanner} must be overridden from the @code{\paper} block, since the @internalsref{SpacingSpanner} is created before any property commands are interpreted. @example \paper @{ \context @{ \Score \override SpacingSpanner #'spacing-increment = #3.0 @} @} @end example @seealso Internals: @internalsref{SpacingSpanner}, @internalsref{NoteSpacing}, @internalsref{StaffSpacing}, @internalsref{SeparationItem}, and @internalsref{SeparatingGroupSpanner}. @refbugs Spacing is determined on a score wide basis. If you have a score that changes its character (measured in durations) halfway during the score, the part containing the longer durations will be spaced too widely. There is no convenient mechanism to manually override spacing. The following work-around may be used to insert extra space into a score. @example \once \override Score.SeparationItem #'padding = #1 @end example No work-around exists for decreasing the amount of space. @menu * Line breaking:: * Page layout:: @end menu @node Line breaking @subsection Line breaking @cindex line breaks @cindex breaking lines Line breaks are normally computed automatically. They are chosen such that lines look neither cramped nor loose, and that consecutive lines have similar density. Occasionally you might want to override the automatic breaks; you can do this by specifying @code{\break}. This will force a line break at this point. Line breaks can only occur at places where there are bar lines. If you want to have a line break where there is no bar line, you can force an invisible bar line by entering @code{\bar ""}. Similarly, @code{\noBreak} forbids a line break at a point. @cindex regular line breaks @cindex four bar music. For line breaks at regular intervals use @code{\break} separated by skips and repeated with @code{\repeat}: @example << \repeat unfold 7 @{ s1 \noBreak s1 \noBreak s1 \noBreak s1 \break @} @emph{the real music} >> @end example @noindent This makes the following 28 measures (assuming 4/4 time) be broken every 4 measures, and only there. @refcommands @code{\break}, and @code{\noBreak}. @cindex @code{\break} @cindex @code{\noBreak} @seealso Internals: @internalsref{BreakEvent}. @node Line length and line breaking @subsection Line length and line breaking @cindex page breaks @cindex breaking pages @cindex @code{indent} @cindex @code{linewidth} The most basic settings influencing the spacing are @code{indent} and @code{linewidth}. They are set in the @code{\paper} block. They control the indentation of the first line of music, and the lengths of the lines. If @code{raggedright} is set to true in the @code{\paper} block, then the lines are justified at their natural length. This useful for short fragments, and for checking how tight the natural spacing is. @cindex page layout @cindex vertical spacing The option @code{raggedlast} is similar to @code{raggedright}, but only affects the last line of the piece. No restrictions are put on that line. The result is similar to formatting paragraphs. In a paragraph, the last line simply takes its natural length. @node Titling @subsection Titling Titles are created for each @code{\score} block, and over a @code{\book}. The contents of the titles are taken from the @code{\header} blocks. The header block for a book supports the following @table @code @item title The title of the music. Centered on top of the first page. @item subtitle Subtitle, centered below the title. @item poet Name of the poet, left flushed below the subtitle. @item composer Name of the composer, right flushed below the subtitle. @item meter Meter string, left flushed below the poet. @item opus Name of the opus, right flushed below the composer. @item arranger Name of the arranger, right flushed below the opus. @item instrument Name of the instrument, centered below the arranger. @item dedication To whom the piece is dedicated. @item piece Name of the piece, left flushed below the instrument. @end table This is a demonstration of the fields available, @lilypond[verbatim] \book { \header { title = "Title" subtitle = "(and (the) subtitle)" subsubtitle = "Sub sub title" poet = "Poet" composer = "Composer" texttranslator = "Text Translator" meter = "Meter" arranger = "Arranger" instrument = "Instrument" piece = "Piece" } \score { \header { piece = "piece1" opus = "opus1" } { c'1 } } \score { \header { piece = "piece2" opus = "opus2" } { c'1 } } } @end lilypond Different fonts may be selected for each element, by using a @code{\markup}, e.g. @verbatim \header { title = \markup { \italic { The italic title } } } @end verbatim A more advanced option is to change the Scheme functions @code{make-book-title} and @code{make-score-title} functions, defined in the @code{\bookpaper} of the @code{\book} block. These functions create a block of titling, given the information in the @code{\header}. The init file @file{ly/titling.scm} shows how the default format is created, and it may be used as a template for different styles. @cindex \bookpaper @cindex header @cindex footer @cindex page layout @cindex titles @node Page breaking @subsection Page breaking The default page breaking may be overriden by inserting @code{\pageBreak} or @code{\noPageBreak} commands. These commands are analogous to @code{\break} and @code{\noBreak}. They should be inserted with a bar line. These commands force and forbid a page-break from happening. Page breaks are computed by the @code{page-breaking} function in the @code{\bookpaper} block. @refcommands @cindex @code{\pageBreak} @code{\pageBreak} @cindex @code{\noPageBreak} @code{\noPageBreak} @node Paper size @subsection Paper size @cindex paper size @cindex page size @cindex @code{papersize} To change the paper size, there are two commands, @example #(set-default-paper-size "a4") \paper@{ #(set-paper-size "a4") @} @end example The second one sets the size of the @code{\paper} block that it is in. @node Page layout @subsection Page layout @cindex page layout @cindex margins @cindex header, page @cindex footer, page LilyPond will do page layout, setting margins and adding headers and footers to each page. The default layout responds to the following settings in the @code{\bookpaper} block @cindex \bookpaper @table @code @item hsize The width of the page @item vsize The height of the page @item topmargin Margin between header and top of the page @item bottommargin Margin between footer and bottom of the page @item leftmargin Margin between the left side of the page and the beginning of the music. @item linewidth The length of the paper line. @item headsep Distance between top-most music system and the page header @item footsep Distance between bottom-most music system and the page footer @item raggedbottom If set to true, systems will not be spread across the page. @item raggedlastbottom If set to true, systems will not be spread to fill the last page. @end table @example \bookpaper@{ hsize = 2\cm topmargin = 3\cm bottommargin = 3\cm raggedlastbottom = ##t @} @end example You can also define these values in scheme. In that case @code{mm}, @code{in}, @code{pt} and @code{cm} are variables defined in @file{book-paper-defaults.ly} with values in millimeters. That's why the value has to be multiplied in the example above. @example \bookpaper@{ #(define bottommargin (* 2 cm)) @} @end example @refbugs The option rightmargin is defined but doesn't set the right margin yet. The value for the right margin has to be defined adjusting the values of the leftmargin and linewidth. The default page header puts the page number and the @code{instrument} field from the @code{\header} block on a line. @cindex copyright @cindex tagline The default footer is empty, except for the first page, where it the @code{copyright} field from @code{\header} is inserted, and the last page, where @code{tagline} from @code{\header} is added. The default tagline is ``Engraved by LilyPond (@var{version})''. The header and footer are created by the functions @code{make-footer} and @code{make-header}, defined in @code{\bookpaper}. The default implementations are in @file{scm/page-layout.scm}. The following settings influence the header and footer layout. @table @code @item printpagenumber this boolean controls whether a pagenumber is printed. @end table The page layout itself is done by two functions: @code{page-music-height} and @code{page-make-stencil}. The former tells the line-breaking algorithm how much space can be spent on a page, the latter creates the actual page given the system to put on it. @seealso Examples: @inputfileref{input/test/,page-breaks.ly}