COMMENT(-*-text-*-)

DEFINEMACRO(var)(1)(whenlatex(latexcommand({\normalfont\scshape )ARG1+latexcommand(}))\
    whenhtml(sc(ARG1)))



COMMENT( This document contains Mudela fragments.  You need at least
Yodl-1.30.18 to convert this to tex or html.

TODO

in stead <-> instead
)

htmlbodyopt(bgcolor)(white)
htmlcommand(<font color=black>)

latexpackage()(a4wide)
latexlayoutcmds(
%\usepackage[latin1]{inputenc}
\input mudela-book
)

whenlatex(notableofcontents())
whentexinfo(notableofcontents())

report(Mudela, reference manual)
      (Han-Wen Nienhuys and Jan Nieuwenhuizen)
      (nop()PIPETHROUGH(date "+%B %d, %Y")()()nop())

COMMENT(

* The [ ] look weird

* paragraphs have too much space.

)


latexcommand(\def\interexample{})
latexcommand(\def\preexample{\par})
latexcommand(\def\postexample{\par\medskip})
latexcommand(\def\file#1{{code(#1)}})
COMMENT(
latexcommand(\def\texttt#1{\tt #1})
latexcommand(\def\textbf#1{\bf #1})
)


bf(This document is not up to date).  All rendered examples of course
are current, but the rest probably isn't.  Adjusting the tutorial was
considered more important than writing the reference manual.  We
apologize for the inconvenience.


This document describes the the GNU LilyPond input format, which is an
effective language for defining music.  We call this language (rather
arrogantly) The Musical Definition Language or Mudela, for
short.footnote(If anybody comes up with a better name, we'd gladly
  take this. Gourlay already uses Musical Description Language,
  G-Sharp Score Definition Language.  ISO standard 10743 defines a
  Standard Music Description Language.  We're not being original here.)

The first aim of Mudela is to define a piece of music, being complete
from both from a musical typesetting, as from a musical performing
point of view.

The Musical Definition Language (Mudela), has a logical structure,
making use of identifiers, that allows for flexible input, and
definition reuse. See the documentation file file(MANIFESTO), included
with the LilyPond sources for reasons and design considerations.

The below is included for explanatory purposes only (i.e., for a
complete and up-to-date definition, see file(lily/parser.yy) and
file(lily/lexer.ll)).

As a related note, you should take a look at the examples and the init
files, as this document does not cover every aspect of Mudela yet, and
may be out of date.footnote(Ok, I am being pessimistic here.  This
just is a disclaimer.  Docs usually are written after the program
itself.)  This document intends to give an idea of how it works. It is
not a guide on how to use it.

sect(Files)

The de-facto extension of Mudela is file(.ly). Files may be included by
entering code(\include) at the start of a line:

verb(
\include "a_file.ly"
)


sect(Comments)

Line comments are introduced by a
code(%).
Block comments are delimited
by 
code(%{)
and
code(%}).
They do not nest.


sect(Versions)

Occasionally, small changes in syntax across different versions of
Mudela might give syntax errors. To warn you about possible
incompatibilities, you can specify the Mudela version for which the
inputfile was written,
verb(
\version "0.0.50";
)

A Python-script which tries to convert to newer versions
(file(convert-mudela)) is included in the LilyPond distribution.

sect(Keywords)

Keywords are preceded by a backslash: code(\). They contain
alphabetic characters only.


sect(Nesting characters)

Mudela uses the brace, `code({)' and `code(})' for most hierarchical
structures.  For chords the code(<) and the code(>) are used as
nesting braces.

sect(Constants)

verb(
"I am a string"
-1.2e3          % a real
12              % an int
)

        
sect(Identifiers)

When assigning identifiers you use

verb(
string = ...
)

If you reuse identifiers, then the previous contents will be thrown
away after the right hand is evaluated, e.g.
verb(
bla = \melodic { \bla }
)
is legal

When using identifiers they have to be escaped:

verb(
oboe = \melodic { ... }
\score{ \melodic { \oboe }}
)

The left-hand part of the assignment is really a string, so 
verb(
"Foo bar 4 2 " = \melodic { .. }
)

is also a valid assignment (but you would have trouble referencing to it)


sect(Hierarchical structures)

The general structure consists of declarations:
verb(
IDENTIFIER = \TYPE{
        <type specific data>
}
)
and instantiations:

verb(
\TYPE{ <type specific data> }
)

(Currently, code(\score) is the only type that can be instantiated
at top level.)

Most instantiations that use an IDENTIFIER are specified as follows:

verb(
\TYPE{ \IDENTIFIER [...] }
)

Some exceptions on this rule have been made to prevent inputting
Mudela becoming tedious

sect(Modes:)

To simplify different aspects of music definition (entering the notes
and manipulating them) Mudela has a number of different input "modes":

description(


dit(Normal mode)

At the start of parsing, Mudela assumes normal mode.
In Normal mode, a word is looked up in the following order:
description(
dit(code(word))    string
dit(code("string")) string
dit(code(\word)) keyword, identifier
)
In normal mode, a word is assumed to start with an alphabetic
character, followed by alpha-numeric characters.

dit(Note mode) Note mode is introduced by the keyword
  code(\melodic).  In Note mode, a word is looked up in the following
  order:
description(
dit(code(word)) notename, string
dit(code("string")) string
dit(code(\word)) keyword, identifier
)

In Note mode a word is considered to have alphabetic characters only,
so the underscore (_) is invalid.  If you accidently mistype a
notename, the parser will assume that you are entering a string (and
it will most likely complain that you should be in code(\lyric) mode to
do lyrics)


dit(Lyric mode) Lyrics mode is introduced by the keyword
  code(\lyric).  Because of the various control characters that can
  appear in lyrics, e.g., foreign language accents, the inputting a
  string containing these has been made very easy.

In Lyrics mode, a word is looked up in the following order:
description(
dit(code(word))    string (thus a lyric)
dit(code("string")) string
dit(code(\word)) keyword, identifier
)

In Lyric mode every sequence of non-digit and non-white characters
starting with an alphabetic character or the _ is considered a word.

verb(
a&@&@&TSI|{[    % a word
1THtrhortho     % not a "word"
Leise DOEXPAND(Fl\)DOEXPAND("u\)ss{}teren meine Sapfe       % 4 words
_ _ _ _         % 4 words: 4 spaces
)
)

These modes are of a lexical nature. Normal and Note mode largely
resemble each other, save the possibility of entering Reals, 
meaning of code(_) and the resolution of words





Durations are entered as their reciprocal values
mudela(fragment,verbatim,center)(
a'1 a'2 a'4 a a'8 a a'16 a'32 a'64
)
Notice that you only have to specify the duration when it changes: Lily
assumes a note has the same duration as the previous one.

Now we can already write a little tune
mudela(fragment,verbatim,center)(
c' d' e' c' | c' d' e' c' | e' f' g'2
)
As you'll probably have guessed,
the vertical bar  code(|) may be used to mark
measures.

In the scale shown above
we left-out the last c note of the next octave.
Postfixing the pitch with a quote code(')
produces a note by one octave higher
mudela(fragment,verbatim,center)(
c c' c''
)

Postfixing the pitch with a comma, code(,)
produces a note by one octave lower
mudela(fragment,verbatim,center)(
a a, a,,
)

sect(Slurs and Ties)

A tie connects two adjacent note heads

mudela(fragment,verbatim,center)(
e' ~ e'
)

Whereas a slur rather connects `chords', 
and tries to avoid crossing stems

mudela(fragment,verbatim,center)(
e'( )e'
)

And of course, such a (legato) slur can span several notes
mudela(fragment,verbatim,center)(
c'( d' e' )f'
)

sect(Beams and Tuplets)

A beam is 
mudela(fragment,verbatim,center)(
[a'8 a'] [a'16 a' a' a']
)

Here's a beamed triplet
mudela(fragment,verbatim,center)(
[/3 a'8 a' a']/1
)

a triplet without a beam
mudela(fragment,verbatim,center)(
\[/3 a'4 a'8\]
)

and a combination
mudela(fragment,verbatim,center)(
[/3 a'8 a'16 a'] a'8 \]
)

Abbreviations
mudela(fragment,verbatim,center)(
c'1:16 [:16 e'1 g']
)

mudela(fragment,verbatim,center)(
c'4:32 [:16 c'8 d'8]
)

sect(Notenames)

Lily has predefined sets of notenames
for various nop(languages)footnote(These 
are Dutch, English, German, Italian and Swedish.
Simply include the language specific init file file(language.ly).).
The default set are the ones we like best are the Dutch notenames.

A sharp is formed by adding code(is)
mudela(fragment,verbatim,center)(
cis' dis' eis' fis' gis' ais' bis'
)

and a flat is formed by adding code(es)
mudela(fragment,verbatim,center)(
ces' des' es' fes' ges' as' bes'
)

With the obvious names for double sharps
mudela(fragment,verbatim)(
cisis' disis' eisis' fisis' gisis' aisis' bisis'
)

and double flats
mudela(fragment,verbatim)(
ceses' deses' eses' feses' geses' ases' beses'
)


There are two special `notenames', the rest
mudela(fragment,verbatim,center)(
r16 [a' a' a']
)

and the space
mudela(fragment,verbatim,center)(
a'2 s-"diminuendo" | a'
)


sect(Commands)

mudela(fragment,verbatim,center)(
\clef "bass"; c
)

and a clef-change
mudela(fragment,verbatim,center)(
\clef "treble"; f' e' \clef "alto"; d' c'
)

mudela(fragment,verbatim,center)(
\time 3/4; c' g' g' |
)

mudela(fragment,verbatim,center)(
\key d;
g a b cis' d' e' fis' g'
)
Note how Mudela allows you to 
convey a musical message and doesn't force  you to produce a list of typesetting commands.
If the music has a code(cis), you type a code(cis).
Depending on the key and context of the note
Lily will determine what accidentals to typeset.

A reminder accidental can be forced by
using an exclamation mark code(!)
on a pitch a reminder accidental
mudela(fragment,verbatim,center)(
cis' d' e' cis' | c'! d' e' c' |
)

mudela(fragment,verbatim)(
\time 2/4;
\bar "|:"; c' c' \bar ":|:"; c' c' \bar ":|"; c' c' \bar "|."; 
)

sect(Chords and Voices)

Here's a simple chord
mudela(fragment,verbatim,center)(
<c e g>
)

here are a few
mudela(fragment,verbatim,center)(
<
        { c'()d'()c' }
        { e'()f'()e' }
        { g'()a'()g' }
>
)

and similarly voices
mudela(fragment,verbatim)(
<
        { \voiceone c'4 g' c' g' }
        { \voicetwo c2 g2 }
>
)


sect(A complete example)
COMMENT(%label(se:complete))

A Mudela file needs some red tape

mudela(verbatim)(
\score{
        \melodic {
                c' d' e' c' |
                c' d' e' c' |
                e' f' g'2 |
        }
}
)

sect(Lyrics)

Lyrics are entered like notes, with pitches substituted
by text. 

All syllables are entered separately, separated by whitespace 
verb(
Twin-4 kle4 twin-4 kle4 ... 
)

Two syllables or words that compose a single
duration entry are bound together using an underscore 
verb(
He_could4 not4
)


COMMENT(
URG
                        Fr\`e-4 re Ja- que
                        Fr\`e- re Ja- que
)

mudela(verbatim,center)(
\score{
        < 
                \melodic  \transpose c''  {
                        c d e c | c d e c |
                        e f g'2 | e'4 f g'2
                        \bar "|.";
                }
                \type Lyrics \lyric{ 
                        DOEXPAND(Fr\)`e-4 re Ja- que
                        DOEXPAND(Fr\)`e- re Ja- que
                        Dor- mez vous?2
                        Dor-4 mez vous?2
                }
        >
}
)

sect(Composition: forming bigger structures)
label(sec:grammar)

The computer savy user may be interested in a more formal
specification.  We can capture what have learned about forming
sentences in Mudela in a context-free grammar.

latexcommand(\smallskip)

table(2)(lll)(
        row(cell(em(Music))cell(: em(Note)))
        row(cell()cell(code(|) em(Rest)))
        row(cell()cell(code(|) code({) em(MusicList) code(})))
        row(cell()cell(code(|) code(<) em(MusicList) code(>)))
        row(cell()cell(code(|) em(Command)))
        row(cell()cell(code(|) code(\type) em(string) code(=) em(string)  em(Music)))
        row(cell()cell(;))
        row(cell(em(MusicList))cell(: em(empty)))
        row(cell()cell(code(|)  em(MusicList)  em(Music)))
	row(cell()cell(;))
)

latexcommand(\smallskip)





In mathematics you can form expressions by combining expressions,
which are ultimately some kind of atom or terminal symbol.  The same
goes for Mudela: there are some basic building blocks, and by
combining those you create complex music.

You can combine music in three ways:
itemize(
it()If you enclose a sequence of music-elements in braces ( code({)
    and code(}) ), then you form another kind of music called
sequential music
    with those pieces.
  The duration of sequential composition is the sum of the durations of its elements
  verb(
      { c c g g a a g2 }      % twinkle twinkle
      { { c c g g} { a a g2 } }
  )
it()You can stack music by enclosing a sequence of music elements
    with code(<) and code(>). This is called simultaneous music.  
    The duration of a simultaneous composition is the union of the durations 
    of its elements Example:
    verb(
        <a4 {cis8 cis8} e'4>      % a-major chord
    )
it()You can form music by transposing music:
    verb(
    \transpose  
        d       % from c to the d that's almost one octave down
                { e4 f4 }       % the horizontal music
)
it()verb(\type)
it()verb(\property)
it()verb(\translator)
it()verb(\relative)
)

Of course you can also combine these three mechanisms.
verb(
{ c <c e> <c e g> <c e g \transpose d' dis > }  % 4 increasing chords
)


sect(Durations)

A duration always starts with the duration type (1,2,4 etc), and then
any optional multipliers/dots.  `Gregrorian' durations can be entered
as follows
verb(
c'\breve
gis'\longa
)


        
sect(Time signatures/groupings)

A time signature specification has this form:
verb(
\time 3/4 ;
)

Rhythmic grouping is  a concept closely associated with this. For
example, in a 5/8 time signature, the counts are grouped 2+3. In Mudela this is
entered as
verb(
\grouping  8*2 8*3 ;
)

You can start the piece with a partial measure, the command takes a
duration as an argument
verb(
\partial 16*3;
)

Make the piece start with a upstep 
lasting 1 3/4 quarter notes.

These commands  constitute `Music', and have a duration of 0.


sect(Properties)

By default the same key signature is valid for all octaves, but
  this can be changed with the property code(keyoctaviation).


The identifier code(\specialkey) sets the property for the Staff.  A
key with two flats in one octave and three sharps in the next can be 
declared with verb(\specialkey \keysignature bes es fis' cis' gis';)

sect(Music fragments)
label(tutorial:music-fragments)

Sometimes you only need to print a small fragment of music, perhaps 
something much like one of the examples in this document.  Back in
section ref(sec:running-lilypond) we told you that the music you
enter should be encapsulated in something like:
verb(
\score<
        \melodic\relative c{
		d
	}
	\paper{ }
	\midi{ }
>
)
where the only interesting information is this particular example is verb(
	d
)
The rest of the above example was already nicknamed `red tape'.
You may easily get bored if you have to provide this same red tape 
for every fragmenty you nop(try)footnote(Of course, in most cases your
favourite text editor (TM)
will help you out.).

Luckily there's a trick around this, and it's called file(.fly) files.
If you use the extension file(.fly) for Mudela file file(foo),
LilyPond will embed your file(foo.fly) nop(in)footnote(Or something very 
similar.  If you want to know exactly, see file(init/init.fly)):
verb(
\score<
        \melodic\relative c{
		<<foo.ly>>
	}
	\paper{ }
	\midi{ }
)

Here's how it works.  If you run LilyPond on your file file(bar.ly), you
may notice that she starts-off by reading quite a number of files before
she actually reaches your file(bar.ly).  There's no magic going on, Lily
by default reads an initialisation file (file(init/init.ly)).  In the
initialisation process a lot of things are defined that you'll need for 
normal operation, such as notenames and various other mudela shortcuts,
engraver and perforer definitions, font sizes, musical dimensions and 
paper sizes.  When you use the extension file(.fly), Lily just starts
reading another initialisation file (file(init/init.fly)), that includes the 
red tape for you too.