@c -*- coding: utf-8; mode: texinfo; -*- @c This file is part of lilypond-learning.tely @ignore Translation of GIT committish: FILL-IN-HEAD-COMMITTISH When revising a translation, copy the HEAD committish of the version that you are working on. See TRANSLATION for details. @end ignore @c \version "2.11.51" @node Introduction @chapter Introduction This chapter introduces readers to LilyPond and the documentation. @menu * Background:: * About the documentation:: @end menu @node Background @section Background This section covers the overall goals and architecture of LilyPond. @menu * Engraving:: * Automated engraving:: * What symbols to engrave?:: * Music representation:: * Example applications:: @end menu @node Engraving @unnumberedsubsec Engraving The art of music typography is called @emph{(plate) engraving}. The term derives from the traditional process of music printing. Just a few decades ago, sheet music was made by cutting and stamping the music into a zinc or pewter plate in mirror image. The plate would be inked, the depressions caused by the cutting and stamping would hold ink. An image was formed by pressing paper to the plate. The stamping and cutting was completely done by hand. Making a correction was cumbersome, if possible at all, so the engraving had to be perfect in one go. Engraving was a highly specialized skill; a craftsman had to complete around five years of training before earning the title of master engraver, and another five years of experience were necessary to become truly skilled. Nowadays, all newly printed music is produced with computers. This has obvious advantages; prints are cheaper to make, and editorial work can be delivered by email. Unfortunately, the pervasive use of computers has also decreased the graphical quality of scores. Computer printouts have a bland, mechanical look, which makes them unpleasant to play from. @c introduce illustrating aspects of engraving, font... The images below illustrate the difference between traditional engraving and typical computer output, and the third picture shows how LilyPond mimics the traditional look. The left picture shows a scan of a flat symbol from an edition published in 2000. The center depicts a symbol from a hand-engraved Bärenreiter edition of the same music. The left scan illustrates typical flaws of computer print: the staff lines are thin, the weight of the flat symbol matches the light lines and it has a straight layout with sharp corners. By contrast, the Bärenreiter flat has a bold, almost voluptuous rounded look. Our flat symbol is designed after, among others, this one. It is rounded, and its weight harmonizes with the thickness of our staff lines, which are also much thicker than lines in the computer edition. @multitable @columnfractions .125 .25 .25 .25 .125 @item @tab @ifnotinfo @iftex @image{henle-flat-gray,,4cm} @end iftex @ifnottex @image{henle-flat-gray,,,png} @end ifnottex @tab @iftex @image{baer-flat-gray,,4cm} @end iftex @ifnottex @image{baer-flat-gray,,,png} @end ifnottex @tab @iftex @image{lily-flat-bw,,4cm} @end iftex @ifnottex @image{lily-flat-bw,,,png} @end ifnottex @end ifnotinfo @ifinfo @image{lilypond/henle-flat-bw,,,png} @image{lilypond/baer-flat-bw,,,png} @image{lilypond/lily-flat-bw,,,png} @end ifinfo @item @tab Henle (2000) @tab Bärenreiter (1950) @tab LilyPond Feta font (2003) @end multitable @cindex musical symbols @cindex font @cindex blackness @cindex balance @c introduce illustrating aspects of engraving, spacing... In spacing, the distribution of space should reflect the durations between notes. However, many modern scores adhere to the durations with mathematical precision, which leads to poor results. In the next example a motive is printed twice: once using exact mathematical spacing, and once with corrections. Can you spot which fragment is which? @cindex optical spacing @c file spacing-optical. @c need to include it here, because we want two images. @lilypond \paper { ragged-right = ##t indent = #0.0 } music = { c'4 e''4 e'4 b'4 | \stemDown b'8[ e'' a' e''] \stemNeutral e'8[ e'8 e'8 e'8] } \score { \music \layout { \context { \Staff \override NoteSpacing #'stem-spacing-correction = #0.6 } } } @end lilypond @lilypond \paper { ragged-right = ##t indent = #0.0 } music = { c'4 e''4 e'4 b'4 | \stemDown b'8[ e'' a' e''] \stemNeutral e'8[ e'8 e'8 e'8] } \score { \music \layout { \context { \Staff \override NoteSpacing #'stem-spacing-correction = #0.0 \override NoteSpacing #'same-direction-correction = #0.0 \override StaffSpacing #'stem-spacing-correction = #0.0 } } } @end lilypond @cindex regular rhythms @cindex regular spacing Each bar in the fragment only uses notes that are played in a constant rhythm. The spacing should reflect that. Unfortunately, the eye deceives us a little; not only does it notice the distance between note heads, it also takes into account the distance between consecutive stems. As a result, the notes of an up-stem/@/down-stem combination should be put farther apart, and the notes of a down-stem/@/up-stem combination should be put closer together, all depending on the combined vertical positions of the notes. The upper two measures are printed with this correction, the lower two measures without, forming down-stem/@/up-stem clumps of notes. @cindex typography Musicians are usually more absorbed with performing than with studying the looks of a piece of music, so nitpicking about typographical details may seem academical. But it is not. In larger pieces with monotonous rhythms, spacing corrections lead to subtle variations in the layout of every line, giving each one a distinct visual signature. Without this signature all lines would look the same, and they become like a labyrinth. If a musician looks away once or has a lapse in concentration, the lines might lose their place on the page. Similarly, the strong visual look of bold symbols on heavy staff lines stands out better when the music is far away from the reader, for example, if it is on a music stand. A careful distribution of white space allows music to be set very tightly without cluttering symbols together. The result minimizes the number of page turns, which is a great advantage. This is a common characteristic of typography. Layout should be pretty, not only for its own sake, but especially because it helps the reader in her task. For performance material like sheet music, this is of double importance: musicians have a limited amount of attention. The less attention they need for reading, the more they can focus on playing the music. In other words, better typography translates to better performances. These examples demonstrate that music typography is an art that is subtle and complex, and that producing it requires considerable expertise, which musicians usually do not have. LilyPond is our effort to bring the graphical excellence of hand-engraved music to the computer age, and make it available to normal musicians. We have tuned our algorithms, font-designs, and program settings to produce prints that match the quality of the old editions we love to see and love to play from. @node Automated engraving @unnumberedsubsec Automated engraving How do we go about implementing typography? If craftsmen need over ten years to become true masters, how could we simple hackers ever write a program to take over their jobs? The answer is: we cannot. Typography relies on human judgment of appearance, so people cannot be replaced completely. However, much of the dull work can be automated. If LilyPond solves most of the common situations correctly, this will be a huge improvement over existing software. The remaining cases can be tuned by hand. Over the course of years, the software can be refined to do more and more things automatically, so manual overrides are less and less necessary. When we started, we wrote the LilyPond program entirely in the C++ programming language; the program's functionality was set in stone by the developers. That proved to be unsatisfactory for a number of reasons: @itemize @item When LilyPond makes mistakes, users need to override formatting decisions. Therefore, the user must have access to the formatting engine. Hence, rules and settings cannot be fixed by us at compile-time but must be accessible for users at run-time. @item Engraving is a matter of visual judgment, and therefore a matter of taste. As knowledgeable as we are, users can disagree with our personal decisions. Therefore, the definitions of typographical style must also be accessible to the user. @item Finally, we continually refine the formatting algorithms, so we need a flexible approach to rules. The C++ language forces a certain method of grouping rules that do not match well with how music notation works. @end itemize These problems have been addressed by integrating an interpreter for the Scheme programming language and rewriting parts of LilyPond in Scheme. The current formatting architecture is built around the notion of graphical objects, described by Scheme variables and functions. This architecture encompasses formatting rules, typographical style and individual formatting decisions. The user has direct access to most of these controls. Scheme variables control layout decisions. For example, many graphical objects have a direction variable that encodes the choice between up and down (or left and right). Here you see two chords, with accents and arpeggios. In the first chord, the graphical objects have all directions down (or left). The second chord has all directions up (right). @lilypond[quote,ragged-right] \new Score \with { \override SpacingSpanner #'spacing-increment = #3 \override TimeSignature #'transparent = ##t } \relative c' { \stemDown 4_>-\arpeggio \override Arpeggio #'direction = #RIGHT \stemUp 4^>-\arpeggio } @end lilypond @noindent The process of formatting a score consists of reading and writing the variables of graphical objects. Some variables have a preset value. For example, the thickness of many lines -- a characteristic of typographical style -- is a variable with a preset value. You are free to alter this value, giving your score a different typographical impression. @lilypond[quote,ragged-right] fragment = { \clef bass f8 as8 c'4-~ c'16 as g f e16 g bes c' des'4 } << \new Staff \fragment \new Staff \with { \override Beam #'thickness = #0.3 \override Stem #'thickness = #0.5 \override Bar #'thickness = #3.6 \override Tie #'thickness = #2.2 \override StaffSymbol #'thickness = #3.0 \override Tie #'extra-offset = #'(0 . 0.3) } \fragment >> @end lilypond Formatting rules are also preset variables: each object has variables containing procedures. These procedures perform the actual formatting, and by substituting different ones, we can change the appearance of objects. In the following example, the rule which note head objects are used to produce their symbol is changed during the music fragment. @lilypond[quote,ragged-right] #(set-global-staff-size 30) #(define (mc-squared grob orig current) (let* ((interfaces (ly:grob-interfaces grob)) (pos (ly:grob-property grob 'staff-position))) (if (memq 'note-head-interface interfaces) (begin (ly:grob-set-property! grob 'stencil ly:text-interface::print) (ly:grob-set-property! grob 'font-family 'roman) (ly:grob-set-property! grob 'text (make-raise-markup -0.5 (case pos ((-5) (make-simple-markup "m")) ((-3) (make-simple-markup "c ")) ((-2) (make-smaller-markup (make-bold-markup "2"))) (else (make-simple-markup "bla"))))))))) \new Voice \relative c' { \stemUp \set autoBeaming = ##f \time 2/4 4 \once \override NoteHead #'stencil = #ly:note-head::brew-ez-stencil \once \override NoteHead #'font-size = #-7 \once \override NoteHead #'font-family = #'sans \once \override NoteHead #'font-series = #'bold \once \override NoteHead #'style = #'cross \applyOutput #'Voice #mc-squared << { d8[ es-( fis^^ g] fis2-) } \repeat unfold 5 { \applyOutput #'Voice #mc-squared s8 } >> } @end lilypond @node What symbols to engrave? @unnumberedsubsec What symbols to engrave? @cindex engraving @cindex typography The formatting process decides where to place symbols. However, this can only be done once it is decided @emph{what} symbols should be printed, in other words what notation to use. Common music notation is a system of recording music that has evolved over the past 1000 years. The form that is now in common use dates from the early renaissance. Although the basic form (i.e., note heads on a 5-line staff) has not changed, the details still evolve to express the innovations of contemporary notation. Hence, it encompasses some 500 years of music. Its applications range from monophonic melodies to monstrous counterpoints for large orchestras. How can we get a grip on such a many-headed beast, and force it into the confines of a computer program? Our solution is to break up the problem of notation (as opposed to engraving, i.e., typography) into digestible and programmable chunks: every type of symbol is handled by a separate module, a so-called plug-in. Each plug-in is completely modular and independent, so each can be developed and improved separately. Such plug-ins are called @code{engraver}s, by analogy with craftsmen who translate musical ideas to graphic symbols. In the following example, we see how we start out with a plug-in for note heads, the @code{Note_heads_engraver}. @lilypond[quote,ragged-right] \include "engraver-example.ily" \score { \topVoice \layout { \context { \Voice \remove "Stem_engraver" \remove "Phrasing_slur_engraver" \remove "Slur_engraver" \remove "Script_engraver" \remove "Beam_engraver" \remove "Auto_beam_engraver" } \context { \Staff \remove "Accidental_engraver" \remove "Key_engraver" \remove "Clef_engraver" \remove "Bar_engraver" \remove "Time_signature_engraver" \remove "Staff_symbol_engraver" \consists "Pitch_squash_engraver" } } } @end lilypond @noindent Then a @code{Staff_symbol_engraver} adds the staff @lilypond[quote,ragged-right] \include "engraver-example.ily" \score { \topVoice \layout { \context { \Voice \remove "Stem_engraver" \remove "Phrasing_slur_engraver" \remove "Slur_engraver" \remove "Script_engraver" \remove "Beam_engraver" \remove "Auto_beam_engraver" } \context { \Staff \remove "Accidental_engraver" \remove "Key_engraver" \remove "Clef_engraver" \remove "Bar_engraver" \consists "Pitch_squash_engraver" \remove "Time_signature_engraver" } } } @end lilypond @noindent the @code{Clef_engraver} defines a reference point for the staff @lilypond[quote,ragged-right] \include "engraver-example.ily" \score { \topVoice \layout { \context { \Voice \remove "Stem_engraver" \remove "Phrasing_slur_engraver" \remove "Slur_engraver" \remove "Script_engraver" \remove "Beam_engraver" \remove "Auto_beam_engraver" } \context { \Staff \remove "Accidental_engraver" \remove "Key_engraver" \remove "Bar_engraver" \remove "Time_signature_engraver" } } } @end lilypond @noindent and the @code{Stem_engraver} adds stems. @lilypond[quote,ragged-right] \include "engraver-example.ily" \score { \topVoice \layout { \context { \Voice \remove "Phrasing_slur_engraver" \remove "Slur_engraver" \remove "Script_engraver" \remove "Beam_engraver" \remove "Auto_beam_engraver" } \context { \Staff \remove "Accidental_engraver" \remove "Key_engraver" \remove "Bar_engraver" \remove "Time_signature_engraver" } } } @end lilypond @noindent The @code{Stem_engraver} is notified of any note head coming along. Every time one (or more, for a chord) note head is seen, a stem object is created and connected to the note head. By adding engravers for beams, slurs, accents, accidentals, bar lines, time signature, and key signature, we get a complete piece of notation. @lilypond[quote,ragged-right] \include "engraver-example.ily" \score { \topVoice } @end lilypond This system works well for monophonic music, but what about polyphony? In polyphonic notation, many voices can share a staff. @lilypond[quote,ragged-right] \include "engraver-example.ily" \new Staff << \topVoice \\ \botVoice >> @end lilypond In this situation, the accidentals and staff are shared, but the stems, slurs, beams, etc., are private to each voice. Hence, engravers should be grouped. The engravers for note heads, stems, slurs, etc., go into a group called @q{Voice context,} while the engravers for key, accidental, bar, etc., go into a group called @q{Staff context.} In the case of polyphony, a single Staff context contains more than one Voice context. Similarly, multiple Staff contexts can be put into a single Score context. The Score context is the top level notation context. @seealso Internals Reference: @rinternals{Contexts}. @lilypond[quote,ragged-right] \include "engraver-example.ily" \score { << \new Staff << \topVoice \\ \botVoice >> \new Staff << \pah \\ \hoom >> >> } @end lilypond @node Music representation @unnumberedsubsec Music representation Ideally, the input format for any high-level formatting system is an abstract description of the content. In this case, that would be the music itself. This poses a formidable problem: how can we define what music really is? Instead of trying to find an answer, we have reversed the question. We write a program capable of producing sheet music, and adjust the format to be as lean as possible. When the format can no longer be trimmed down, by definition we are left with content itself. Our program serves as a formal definition of a music document. The syntax is also the user-interface for LilyPond, hence it is easy to type: @example @{ c'4 d'8 @} @end example @noindent to create a quarter note C1 (middle C) and an eighth note D1 (D above middle C). @lilypond[quote] { c'4 d'8 } @end lilypond On a microscopic scale, such syntax is easy to use. On a larger scale, syntax also needs structure. How else can you enter complex pieces like symphonies and operas? The structure is formed by the concept of music expressions: by combining small fragments of music into larger ones, more complex music can be expressed. For example @lilypond[quote,verbatim,fragment,relative=1] f4 @end lilypond @noindent Simultaneous notes can be constructed by enclosing them with @code{<<} and @code{>>}: @example <> @end example @lilypond[quote,fragment,relative=1] \new Voice { <> } @end lilypond @noindent This expression is put in sequence by enclosing it in curly braces @code{@{@tie{}@dots{}@tie{}@}}: @example @{ f4 <> @} @end example @lilypond[quote,relative=1,fragment] { f4 <> } @end lilypond @noindent The above is also an expression, and so it may be combined again with another simultaneous expression (a half note) using @code{<<}, @code{\\}, and @code{>>}: @example << g2 \\ @{ f4 <> @} >> @end example @lilypond[quote,fragment,relative=2] \new Voice { << g2 \\ { f4 <> } >> } @end lilypond Such recursive structures can be specified neatly and formally in a context-free grammar. The parsing code is also generated from this grammar. In other words, the syntax of LilyPond is clearly and unambiguously defined. User-interfaces and syntax are what people see and deal with most. They are partly a matter of taste, and also subject of much discussion. Although discussions on taste do have their merit, they are not very productive. In the larger picture of LilyPond, the importance of input syntax is small: inventing neat syntax is easy, while writing decent formatting code is much harder. This is also illustrated by the line-counts for the respective components: parsing and representation take up less than 10% of the source code. @node Example applications @unnumberedsubsec Example applications We have written LilyPond as an experiment of how to condense the art of music engraving into a computer program. Thanks to all that hard work, the program can now be used to perform useful tasks. The simplest application is printing notes. @lilypond[quote,relative=1] { \time 2/4 c4 c g'4 g a4 a g2 } @end lilypond @noindent By adding chord names and lyrics we obtain a lead sheet. @lilypond[quote,ragged-right] << \chords { c2 c f2 c } \new Staff \relative c' { \time 2/4 c4 c g'4 g a4 a g2 } \new Lyrics \lyricmode { twin4 kle twin kle lit tle star2 } >> @end lilypond Polyphonic notation and piano music can also be printed. The following example combines some more exotic constructs. @lilypond[quote] \header { title = "Screech and boink" subtitle = "Random complex notation" composer = "Han-Wen Nienhuys" } \score { \context PianoStaff << \new Staff = "up" { \time 4/8 \key c \minor << { \revert Stem #'direction \change Staff = down \set subdivideBeams = ##t g16.[ \change Staff = up c'''32 \change Staff = down g32 \change Staff = up c'''32 \change Staff = down g16] \change Staff = up \stemUp \set followVoice = ##t c'''32([ b''16 a''16 gis''16 g''32)] } \\ { s4 \times 2/3 { d'16[ f' g'] } as'32[ b''32 e'' d''] } \\ { s4 \autoBeamOff d''8.. f''32 } \\ { s4 es''4 } >> } \new Staff = "down" { \clef bass \key c \minor \set subdivideBeams = ##f \override Stem #'french-beaming = ##t \override Beam #'thickness = #0.3 \override Stem #'thickness = #4.0 g'16[ b16 fis16 g16] << \makeClusters { as16 } \\ { \override Staff.Arpeggio #'arpeggio-direction =#down 4\arpeggio } >> } >> \midi { \context { \Score tempoWholesPerMinute = #(ly:make-moment 60 8) } } \layout { \context { \Staff \consists Horizontal_bracket_engraver } } } @end lilypond The fragments shown above have all been written by hand, but that is not a requirement. Since the formatting engine is mostly automatic, it can serve as an output means for other programs that manipulate music. For example, it can also be used to convert databases of musical fragments to images for use on websites and multimedia presentations. This manual also shows an application: the input format is text, and can therefore be easily embedded in other text-based formats such as @LaTeX{}, HTML, or in the case of this manual, Texinfo. By means of a special program, the input fragments can be replaced by music images in the resulting PDF or HTML output files. This makes it easy to mix music and text in documents. @node About the documentation @section About the documentation This section explains the different portions of the documentation. @c leave these lines wrapping around. It's some texinfo 4.12 thing. -gp @c This is actually a limitation of texi2html. -jm @menu * About the Learning Manual (LM):: this manual introduces LilyPond, giving in-depth explanations of how to create notation. * About the Music Glossary (MG):: this manual explains musical terms and gives translations of terms in other languages. * About the Notation Reference (NR):: this manual is the main portion of the documentation. It provides detailed information about creating notation. This book assumes that the reader knows basic material covered in the LM and is familiar with the English musical terms presented in the MG. * About the Application Usage (AU):: this discusses the actual programs and operating system-specific issues. * About the Snippet List (SL):: this is a collection of short LilyPond examples. * About the Internals Reference (IR):: this document gives reference information about LilyPond's internal structures, which is required for constructing tweaks. * Other documentation:: there are a few other portions of the documentation, such as News items and the mailist archives. @end menu @node About the Learning Manual (LM) @unnumberedsubsec About the Learning Manual (LM) This book explains how to begin learning LilyPond, as well as explaining some key concepts in easy terms. You should read these chapters in a linear fashion. There is a paragraph @strong{See also} at the end of each section, which contains cross-references to other sections: you should not follow these cross-references at first reading; when you have read all of the Learning Manual, you may want to read some sections again and follow cross-references for further reading. @itemize @item @ref{Introduction}: explains the background and overall goal of LilyPond. @item @ref{Tutorial}: gives a gentle introduction to typesetting music. First time users should start here. @item @ref{Fundamental concepts}: explains some general concepts about the LilyPond file format. If you are not certain where to place a command, read this chapter! @item @ref{Tweaking output}: shows how to change the default engraving that LilyPond produces. @item @ref{Working on LilyPond projects}: discusses practical uses of LilyPond and how to avoid some common problems. Read this before undertaking large projects! @end itemize The LM also contains appendices which are not part of the recommended linear reading. They may be useful for later viewing: @itemize @item @ref{Templates}: shows ready-made templates of LilyPond pieces. Just cut and paste a template into a file, add notes, and you're done! @item @ref{Scheme tutorial}: presents a short introduction to Scheme, the programming language that music functions use. This is material for advanced tweaks; many users never touch Scheme at all. @end itemize @node About the Music Glossary (MG) @unnumberedsubsec About the Music Glossary (MG) @cindex idiom @cindex jargon @cindex terminology @cindex foreign languages @cindex language @rglosnamed{Top,Music glossary} this explains musical terms, and includes translations to various languages. If you are not familiar with music notation or music terminology (especially if you are a non-native English speaker), it is highly advisable to consult the glossary. @node About the Notation Reference (NR) @unnumberedsubsec About the Notation Reference (NR) This book explains all the LilyPond commands which produce notation. It assumes that readers are familiar with the concepts in the Learning manual. @itemize @item @ruser{Musical notation}: discusses topics grouped by notation construct. This section gives details about basic notation that will be useful in almost any notation project. @item @ruser{Specialist notation}: discusses topics grouped by notation construct. This section gives details about special notation that will only be useful for particular instrument (or vocal) groups. @item @ruser{General input and output}: discusses general information about LilyPond input files and controlling output. @item @ruser{Spacing issues}: discusses issues which affect the global output, such as selecting paper size or specifying page breaks. @item @ruser{Changing defaults}: explains how to tweak LilyPond to produce exactly the notation you want. @item @ruser{Interfaces for programmers}: explains how to create music functions with scheme. @end itemize The NR also contains appendices with useful reference charts. @itemize @item @ruser{Literature list}: contains a set of useful reference books for those who wish to know more on notation and engraving. @item @ruser{Notation manual tables}: are a set of tables showing the chord names, MIDI instruments, a list of color names, and the Feta font. @item @ruser{Cheat sheet}: is a handy reference of the most common LilyPond commands. @item @ruser{LilyPond command index}: an index of all LilyPond @code{\commands}. @item @ruser{LilyPond index}: a complete index. @end itemize @node About the Application Usage (AU) @unnumberedsubsec About the Application Usage (AU) This book explains how to execute the programs and how to integrate LilyPond notation with other programs. @itemize @item @rprogram{Install}: explains how to install LilyPond (including compilation if desired). @item @rprogram{Setup}: describes how to configure your computer for optimum LilyPond usage, such as using special environments for certain text editors. @item @rprogram{Running LilyPond}: shows how to run LilyPond and its helper programs. In addition, this section explains how to upgrade input files from previous versions of LilyPond. @item @rprogram{LilyPond-book}: explains the details behind creating documents with in-line music examples, like this manual. @item @rprogram{Converting from other formats}: explains how to run the conversion programs. These programs are supplied with the LilyPond package, and convert a variety of music formats to the @code{.ly} format. @end itemize @node About the Snippet List (SL) @unnumberedsubsec About the Snippet List (SL) @cindex snippets @cindex LSR @rlsrnamed{Top,LilyPond Snippet List}: this shows a selected set of LilyPond snippets from the @uref{http://lsr@/.dsi@/.unimi@/.it,LilyPond Snippet Repository} (LSR). All the snippets are in the public domain. Please note that this document is not an exact subset of LSR. LSR is running a stable LilyPond version, so any snippet which demonstrates new features of a development version must be added separately. These are stored in @file{input/new/} in the LilyPond source tree. The list of snippets for each subsection of the Notation Reference (NR) are also linked from the @strong{See also} portion. @node About the Internals Reference (IR) @unnumberedsubsec About the Internals Reference (IR) @rinternalsnamed{Top,Internals Reference}: this is a set of heavily cross linked HTML pages which document the nitty-gritty details of each and every LilyPond class, object, and function. It is produced directly from the formatting definitions in the source code. Almost all formatting functionality that is used internally is available directly to the user. For example, most variables that control thickness values, distances, etc., can be changed in input files. There are a huge number of formatting options, and all of them are described in this document. Each section of the Notation Reference has a @b{See also} subsection, which refers to the generated documentation. In the HTML document, these subsections have clickable links. @node Other documentation @unnumberedsubsec Other documentation There are a number of other sources of information which may be very valuable. @itemize @item News: This is a summary of important changes and new features in LilyPond since the previous version. @item @uref{http://lists.gnu.org/archive/html/lilypond-user/, The lilypond-user mailist archives}: this is a collection of previous emails sent to the user list. Many questions have been asked multiple times; there is a very good chance that if you have a question, the answer might be found in these archives. @item @uref{http://lists.gnu.org/archive/html/lilypond-devel/, The lilypond-devel mailist archives}: this is a collection of previous emails sent to the developer's list. The discussion here is more technical; if you have an advanced question about lilypond internals, the answer might be in these archives. @item Embedded music fragments: in all HTML documents that have music fragments embedded, the exact LilyPond input that was used to produce that image can be viewed by clicking the image. @item Init files: The location of the documentation files that are mentioned here can vary from system to system. On occasion, this manual refers to initialization and example files. Throughout this manual, we refer to input files relative to the top-directory of the source archive. For example, @file{input/@/lsr/@/dirname/@/bla@/.ly} may refer to the file @file{lilypond@/2.x.y/@/input/@/lsr/@/dirname/@/bla@/.ly}. On binary packages for the UNIX platform, the documentation and examples can typically be found somewhere below @file{/usr/@/share/@/doc/@/lilypond/}. Initialization files, for example @file{scm/@/lily@/.scm}, or @file{ly/@/engraver@/-init@/.ly}, are usually found in the directory @file{/usr/@/share/@/lilypond/}. @end itemize