@c -*- coding: utf-8; mode: texinfo; -*- @node Working on LilyPond projects @chapter Working on LilyPond projects This section explains how to use the rest of the documentation and how to solve common problems. @menu * Suggestions for writing LilyPond files:: * Extending the templates:: * Fixing overlapping notation:: * How LilyPond files work:: * Score is a single musical expression:: * Troubleshooting (taking it all apart):: @end menu @node Suggestions for writing LilyPond files @section Suggestions for writing LilyPond files Now you're ready to begin writing larger LilyPond files -- not just the little examples in the tutorial, but whole pieces. But how should you go about doing it? The best answer is ``however you want to do it.'' As long as LilyPond can understand your files and produces the output that you want, it doesn't matter what your files look like. That said, sometimes we make mistakes when writing files. If LilyPond can't understand your files, or produces output that you don't like, how do you fix the problem? Here are a few suggestions that can help you to avoid or fix problems: @itemize @bullet @item Include @code{\version} numbers in every file. Note that all templates contain a @code{\version "2.7.32"} string. We highly recommend that you always include the @code{\version}, no matter how small your file is. Speaking from personal experience, it's quite frustrating to try to remember which version of LilyPond you were using a few years ago. @code{convert-ly} requires you to declare which version of LilyPond you used. @item Include checks: See @ref{Bar check} and @ref{Octave check}. If you include checks every so often, then if you make a mistake, you can pinpoint it quicker. How often is ``every so often''? It depends on the complexity of the music. For very simple music, perhaps just once or twice. For very complex music, every bar. @item One bar per line of text. If there is anything complicated, either in the music itself or in the output you desire, it's often good to write only one bar per line. Saving screen space by cramming eight bars per line just isn't worth it if you have to `debug' your files. @item Comment your files, with either bar numbers (every so often) or references to musical themes (``second theme in violins'', ``fourth variation''). You may not need it when you're writing the piece for the first time, but if you want to go back and change something two or three years later, you won't know how your file is structured if you didn't comment the file. @item Indent your braces. A lot of problems are caused by an imbalance in the number of @code{@{} and @code{@}}. @end itemize If you are entering music from an existing score (i.e. typesetting a piece of existing sheet music), @itemize @bullet @item Enter one manuscript (the physical copy) system at a time (but still only one bar per line of text), and check each system when you finish it. You may use the @code{showLastLength} command to speed up processing -- see @ref{Skipping corrected music}. @item Define @code{mBreak = @{ \break @}} and insert @code{\mBreak} in the input file whenever the manuscript has a line break. This makes it much easier to compare the LilyPond music to the original music. When you are finished proofreading your score, you may define @code{mBreak = @{ @}} to remove all those line breaks. This will allow LilyPond to place line breaks wherever it feels are best. @end itemize @node Extending the templates @section Extending the templates You've read the tutorial, you know how to write music. But how can you get the staves that you want? The templates are ok, but what if you want something that isn't covered? Start off with the template that seems closest to what you want to end up with. Let's say that you want to write something for soprano and cello. In this case, we would start with ``Notes and lyrics'' (for the soprano part). @example \version "2.7.39" melody = \relative c' @{ \clef treble \key c \major \time 4/4 a4 b c d @} text = \lyricmode @{ Aaa Bee Cee Dee @} \score@{ << \new Voice = "one" @{ \autoBeamOff \melody @} \new Lyrics \lyricsto "one" \text >> \layout @{ @} \midi @{ \tempo 4=60 @} @} @end example Now we want to add a cello part. Let's look at the ``Notes only'' example: @example \version "2.7.39" melody = \relative c' @{ \clef treble \key c \major \time 4/4 a4 b c d @} \score @{ \new Staff \melody \layout @{ @} \midi @{ \tempo 4=60 @} @} @end example We don't need two @code{\version} commands. We'll need the @code{melody} section. We don't want two @code{\score} sections -- if we had two @code{\score}s, we'd get the two parts separately. We want them together, as a duet. Within the @code{\score} section, we don't need two @code{\layout} or @code{\midi}. If we simply cut and paste the @code{melody} section, we would end up with two @code{melody} sections. So let's rename them. We'll call the one for the soprano @code{sopranoMusic}, and the one for the cello can be called @code{celloMusic}. While we're doing this, let's rename @code{text} to be @code{sopranoLyrics}. Remember to rename both instances of all these names -- both the initial definition (the @code{melody = relative c' @{ } part) and the name's use (in the @code{\score} section). While we're doing this, let's change the cello part's staff -- celli normally use bass clef. We'll also give the cello some different notes. @example \version "2.7.39" sopranoMusic = \relative c' @{ \clef treble \key c \major \time 4/4 a4 b c d @} sopranoLyrics = \lyricmode @{ Aaa Bee Cee Dee @} celloMusic = \relative c @{ \clef bass \key c \major \time 4/4 d4 g fis8 e d4 @} \score@{ << \new Voice = "one" @{ \autoBeamOff \sopranoMusic @} \new Lyrics \lyricsto "one" \sopranoLyrics >> \layout @{ @} \midi @{ \tempo 4=60 @} @} @end example This is looking promising, but the cello part won't appear in the score -- we haven't used it in the @code{\score} section. If we want the cello part to appear under the soprano part, we need to add @example \new Staff \celloMusic @end example @noindent underneath the soprano stuff. We also need to add @code{<<} and @code{>>} around the music -- that tells LilyPond that there's more than one thing (in this case staff) happening at once. The @code{\score} looks like this now @example \score@{ << << \new Voice = "one" @{ \autoBeamOff \sopranoMusic @} \new Lyrics \lyricsto "one" \sopranoLyrics >> \new Staff \celloMusic >> \layout @{ @} \midi @{ \tempo 4=60 @} @} @end example @noindent This looks a bit messy; the indentation is messed up now. That is easily fixed. Here's the complete soprano and cello template. @lilypond[quote,verbatim,ragged-right] \version "2.7.39" sopranoMusic = \relative c' { \clef treble \key c \major \time 4/4 a4 b c d } sopranoLyrics = \lyricmode { Aaa Bee Cee Dee } celloMusic = \relative c { \clef bass \key c \major \time 4/4 d4 g fis8 e d4 } \score{ << << \new Voice = "one" { \autoBeamOff \sopranoMusic } \new Lyrics \lyricsto "one" \sopranoLyrics >> \new Staff \celloMusic >> \layout { } \midi { \tempo 4=60 } } @end lilypond @node Fixing overlapping notation @section Fixing overlapping notation This may come as a surprise, but LilyPond isn't perfect. Some notation elements can overlap. This is unfortunate, but (in most cases) is easily solved. @lilypond[quote,fragment,ragged-right,verbatim,relative=2] e4^\markup{ \italic ritenuto } g b e @end lilypond @cindex padding The easiest solution is to increase the distance between the object (in this case text, but it could easily be fingerings or dynamics instead) and the note. In LilyPond, this is called the @code{padding} property; it is measured in staff spaces. For most objects, this value is around 1.0 or less (it varies with each object). We want to increase it, so let's try 1.5 @lilypond[quote,fragment,ragged-right,verbatim,relative=2] \once \override TextScript #'padding = #1.5 e4^\markup{ \italic ritenuto } g b e @end lilypond That looks better, but it isn't quite big enough. After experimenting with a few values, we think 2.3 is the best number in this case. However, this number is merely the result of experimentation and my personal taste in notation. Try the above example with 2.3... but also try higher (and lower) numbers. Which do you think looks the best? @cindex extra-offset Another solution gives us complete control over placing the object -- we can move it horizontally or vertically. This is done with the @code{extra-offset} property. It is slightly more complicated and can cause other problems. When we move objects with @code{extra-offset}, the movement is done after LilyPond has placed all other objects. This means that the result can overlap with other objects. @lilypond[quote,fragment,ragged-right,verbatim,relative=2] \once \override TextScript #'extra-offset = #'( 1.0 . -1.0 ) e4^\markup{ \italic ritenuto } g b e @end lilypond With @code{extra-offset}, the first number controls the horizontal movement (left is negative); the second number controls the vertical movement (up is positive). After a bit of experimenting, we decided that these values look good @lilypond[quote,fragment,ragged-right,verbatim,relative=2] \once \override TextScript #'extra-offset = #'( -1.6 . 1.0 ) e4^\markup{ \italic ritenuto } g b e @end lilypond @noindent Again, these numbers are simply the result of a few experiments and looking at the output. You might prefer the text to be slightly higher, or to the left, or whatever. Try it and look at the result! @seealso This manual: @ref{The \override command}, @ref{Common tweaks}. @node How LilyPond files work @section How LilyPond files work The LilyPond input format is quite free-form, giving experienced users a lot of flexibility to structure their files however they wish. However, this flexibility can make things confusing for new users. This section will explain some of this structure, but may gloss over some details in favor of simplicity. For a complete description of the input format, see @ref{File structure}. Most examples in this manual are little snippets -- for example @example c4 a b c @end example As you are (hopefully) aware by now, this will not compile by itself. These examples are shorthand for complete examples. They all need at least curly braces to compile @example @{ c4 a b c @} @end example Most examples also make use of the @code{\relative c'} (or @code{c''}) command. This is not necessary to merely compile the examples, but in most cases the output will look very odd if you omit the @code{\relative c'}. @lilypond[quote,fragment,ragged-right,verbatim] \relative c'' { c4 a b c } @end lilypond Now we get to the only real stumbling block: LilyPond input in this form is actually @emph{another} shorthand. Although it compiles and displays the correct output, it is shorthand for @example \score @{ \relative c'' @{ c4 a b c @} @} @end example A @code{\score} must begin with a single music expression. Remember that a music expression could be anything from a single note to a huge @example @{ \new GrandStaff << insert the whole score of a Wagner opera in here >> @} @end example @noindent Since everything is inside @code{@{ ... @}}, it counts as one music expression. The @code{\score} can contain other things, such as @example \score @{ @{ c'4 a b c' @} \layout @{ @} \paper @{ @} \midi @{ @} \header @{ @} @} @end example @noindent Most people put some of those commands outside the @code{\score} block -- for example, @code{\header} is almost always placed above the @code{\score}. That's just another shorthand. Another great shorthand is the ability to define variables. All the templates use this @example melody = \relative c' @{ c4 a b c @} \score @{ @{ \melody @} @} @end example When LilyPond looks at this file, it takes the value of @code{melody} (everything after the equals sign) and inserts it whenever it sees @code{\melody}. There's nothing special about the names -- it could be @code{melody}, @code{global}, @code{pianorighthand}, or @code{foofoobarbaz}. You can use whatever variable names you want. For a complete definition of the input format, see @ref{File structure}. @node Score is a single musical expression @section Score is a single musical expression In the previous section, @ref{How LilyPond files work}, we saw the general organization of LilyPond input files. But we seemed to skip over the most important part: how do we figure out what to write after @code{\score}? We didn't skip over it at all. The big mystery is simply that there @emph{is} no mystery. This line explains it all: @example A @code{\score} must begin with a single music expression. @end example @noindent You may find it useful to review @ref{Music expressions explained}. In that section, we saw how to build big music expressions from small pieces -- we started from notes, then chords, etc. Now we're going to start from a big music expression and work our way down. @example \score @{ @{ % this brace begins the overall music expression \new GrandStaff << insert the whole score of a Wagner opera in here >> @} % this brace ends the overall music expression \layout @{ @} @} @end example A whole Wagner opera would easily double the length of this manual, so let's just do a singer and piano. We don't need a @code{GrandStaff} for this ensemble, so we shall remove it. We @emph{do} need a singer and a piano, though. @example \score @{ @{ << \new Staff = "singer" << >> \new PianoStaff = piano << >> >> @} \layout @{ @} @} @end example Remember that we use @code{<<} and @code{>>} to show simultaneous music. And we definitely want to show the vocal part and piano part at the same time! @example \score @{ @{ << \new Staff = "singer" << \new Voice = "vocal" @{ @} >> \new Lyrics \lyricsto vocal \new Lyrics @{ @} \new PianoStaff = "piano" << \new Staff = "upper" @{ @} \new Staff = "lower" @{ @} >> >> @} \layout @{ @} @} @end example Now we have a lot more details. We have the singer's staff: it contains a @code{Voice} (in LilyPond, this term refers to a set of notes, not necessarily vocal notes -- for example, a violin generally plays one voice) and some lyrics. We also have a piano staff: it contains an upper staff (right hand) and a lower staff (left hand). At this stage, we could start filling in notes. Inside the curly braces next to @code{\new Voice = vocal}, we could start writing @example \relative c'' @{ a4 b c d @} @end example But if we did that, the @code{\score} section would get pretty long, and it would be harder to understand what was happening. So let's use identifiers (or variables) instead. @example melody = @{ @} text = @{ @} upper = @{ @} lower = @{ @} \score @{ @{ << \new Staff = "singer" << \new Voice = "vocal" @{ \melody @} >> \new Lyrics \lyricsto vocal \new Lyrics @{ \text @} \new PianoStaff = "piano" << \new Staff = "upper" @{ \upper @} \new Staff = "lower" @{ \lower @} >> >> @} \layout @{ @} @} @end example @noindent Remember that you can use almost any name you like. The limitations on identifier names are detailed in @ref{File structure}. When writing a @code{\score} section, or when reading one, just take it slowly and carefully. Start with the outer layer, then work on each smaller layer. It also really helps to be strict with indentation -- make sure that each item on the same layer starts on the same horizontal position in your text editor! @node Troubleshooting (taking it all apart) @section Troubleshooting (taking it all apart) Sooner or later, you will write a file that LilyPond cannot compile. The messages that LilyPond gives may help you find the error, but in many cases you need to do some investigation to determine the source of the problem. The most powerful tools for this purpose are the single line comment (indicated by @code{%}) and the block comment (indicated by @code{%@{ ... %@}}). If you don't know where a problem is, start commenting out huge portions of your input file. After you comment out a section, try compiling the file again. If it works, then the problem must exist in the portion you just commented. If it doesn't work, then keep on commenting out material until you have something that works. In an extreme case, you might end up with only @example \score @{ << % \melody % \harmony % \bass >> \layout@{@} @} @end example @noindent (in other words, a file without any music) If that happens, don't give up. Uncomment a bit -- say, the bass part -- and see if it works. If it doesn't work, then comment out all of the bass music (but leave @code{\bass} in the @code{\score} uncommented. @example bass = \relative c' @{ %@{ c4 c c c d d d d %@} @} @end example Now start slowly uncommenting more and more of the @code{bass} part until you find the problem line.