First round of doc reorg.

[lilypond.git] / Documentation / user / putting.itely

@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.