1 @c -*- coding: utf-8; mode: texinfo; -*-
2 @c This file is part of lilypond-learning.tely
4 Translation of GIT committish: FILL-IN-HEAD-COMMITTISH
6 When revising a translation, copy the HEAD committish of the
7 version that you are working on. See TRANSLATION for details.
16 * Automated engraving::
17 * What symbols to engrave?::
18 * Music representation::
19 * Example applications::
27 The art of music typography is called @emph{(plate) engraving}. The
28 term derives from the traditional process of music printing. Just a
29 few decades ago, sheet music was made by cutting and stamping the
30 music into a zinc or pewter plate in mirror image. The plate would be
31 inked, the depressions caused by the cutting and stamping would hold
32 ink. An image was formed by pressing paper to the plate. The
33 stamping and cutting was completely done by hand. Making a correction
34 was cumbersome, if possible at all, so the engraving had to be perfect
35 in one go. Engraving was a highly specialized skill; a craftsman had
36 to complete around five years of training before earning the title of
37 master engraver, and another five years of experience were
38 necessary to become truly skilled.
40 Nowadays, all newly printed music is produced with computers. This
41 has obvious advantages; prints are cheaper to make, and editorial work
42 can be delivered by email. Unfortunately, the pervasive use of
43 computers has also decreased the graphical quality of scores.
44 Computer printouts have a bland, mechanical look, which makes them
45 unpleasant to play from.
48 @c introduce illustrating aspects of engraving, font...
49 The images below illustrate the difference between traditional
50 engraving and typical computer output, and the third picture shows how
51 LilyPond mimics the traditional look. The left picture shows a scan
52 of a flat symbol from an edition published in 2000. The center
53 depicts a symbol from a hand-engraved Bärenreiter edition of the
54 same music. The left scan illustrates typical flaws of computer
55 print: the staff lines are thin, the weight of the flat symbol matches
56 the light lines and it has a straight layout with sharp corners. By
57 contrast, the Bärenreiter flat has a bold, almost voluptuous
58 rounded look. Our flat symbol is designed after, among others, this
59 one. It is rounded, and its weight harmonizes with the thickness of
60 our staff lines, which are also much thicker than lines in the
63 @multitable @columnfractions .125 .25 .25 .25 .125
67 @image{henle-flat-gray,,4cm}
70 @image{henle-flat-gray,,,png}
75 @image{baer-flat-gray,,4cm}
78 @image{baer-flat-gray,,,png}
83 @image{lily-flat-bw,,4cm}
86 @image{lily-flat-bw,,,png}
90 @image{lilypond/henle-flat-bw,,,png} @image{lilypond/baer-flat-bw,,,png}
91 @image{lilypond/lily-flat-bw,,,png}
99 LilyPond Feta font (2003)
104 @cindex musical symbols
109 @c introduce illustrating aspects of engraving, spacing...
110 In spacing, the distribution of space should reflect the durations
111 between notes. However, many modern scores adhere to the durations
112 with mathematical precision, which leads to poor results. In the next
113 example a motive is printed twice: once using exact mathematical
114 spacing, and once with corrections. Can you spot which fragment is
117 @cindex optical spacing
118 @c file spacing-optical.
119 @c need to include it here, because we want two images.
140 \override NoteSpacing #'stem-spacing-correction = #0.6
165 \override NoteSpacing #'stem-spacing-correction = #0.0
166 \override NoteSpacing #'same-direction-correction = #0.0
167 \override StaffSpacing #'stem-spacing-correction = #0.0
173 @cindex regular rhythms
174 @cindex regular spacing
176 Each bar in the fragment only uses notes that are played in a constant
177 rhythm. The spacing should reflect that. Unfortunately, the eye
178 deceives us a little; not only does it notice the distance between
179 note heads, it also takes into account the distance between
180 consecutive stems. As a result, the notes of an up-stem/@/down-stem
181 combination should be put farther apart, and the notes of a
182 down-stem/@/up-stem combination should be put closer together, all
183 depending on the combined vertical positions of the notes. The upper
184 two measures are printed with this correction, the lower two measures
185 without, forming down-stem/@/up-stem clumps of notes.
189 Musicians are usually more absorbed with performing than with studying
190 the looks of a piece of music, so nitpicking about typographical
191 details may seem academical. But it is not. In larger pieces with
192 monotonous rhythms, spacing corrections lead to subtle variations in
193 the layout of every line, giving each one a distinct visual signature.
194 Without this signature all lines would look the same, and they become
195 like a labyrinth. If a musician looks away once or has a lapse in
196 concentration, the lines might lose their place on the page.
198 Similarly, the strong visual look of bold symbols on heavy staff lines
199 stands out better when the music is far away from the reader, for
200 example, if it is on a music stand. A careful distribution of white
201 space allows music to be set very tightly without cluttering symbols
202 together. The result minimizes the number of page turns, which is a
205 This is a common characteristic of typography. Layout should be
206 pretty, not only for its own sake, but especially because it helps the
207 reader in her task. For performance material like sheet music, this
208 is of double importance: musicians have a limited amount of attention.
209 The less attention they need for reading, the more they can focus on
210 playing the music. In other words, better typography translates to
213 These examples demonstrate that music typography is an art that is
214 subtle and complex, and that producing it requires considerable
215 expertise, which musicians usually do not have. LilyPond is our
216 effort to bring the graphical excellence of hand-engraved music to the
217 computer age, and make it available to normal musicians. We have
218 tuned our algorithms, font-designs, and program settings to produce
219 prints that match the quality of the old editions we love to see and
225 @node Automated engraving
226 @section Automated engraving
228 How do we go about implementing typography? If craftsmen need over
229 ten years to become true masters, how could we simple hackers ever
230 write a program to take over their jobs?
232 The answer is: we cannot. Typography relies on human judgment of
233 appearance, so people cannot be replaced completely. However, much of
234 the dull work can be automated. If LilyPond solves most of the common
235 situations correctly, this will be a huge improvement over existing
236 software. The remaining cases can be tuned by hand. Over the course
237 of years, the software can be refined to do more and more things
238 automatically, so manual overrides are less and less necessary.
240 When we started, we wrote the LilyPond program entirely in the C++
241 programming language; the program's functionality was set in stone by
242 the developers. That proved to be unsatisfactory for a number of
246 @item When LilyPond makes mistakes,
247 users need to override formatting decisions. Therefore, the user must
248 have access to the formatting engine. Hence, rules and settings cannot
249 be fixed by us at compile-time but must be accessible for users at
252 @item Engraving is a matter of visual judgment, and therefore a matter of
253 taste. As knowledgeable as we are, users can disagree with our
254 personal decisions. Therefore, the definitions of typographical style
255 must also be accessible to the user.
257 @item Finally, we continually refine the formatting algorithms, so we
258 need a flexible approach to rules. The C++ language forces a certain
259 method of grouping rules that do not match well with how music
263 These problems have been addressed by integrating an interpreter for
264 the Scheme programming language and rewriting parts of LilyPond in
265 Scheme. The current formatting architecture is built around the
266 notion of graphical objects, described by Scheme variables and
267 functions. This architecture encompasses formatting rules,
268 typographical style and individual formatting decisions. The user has
269 direct access to most of these controls.
271 Scheme variables control layout decisions. For example, many
272 graphical objects have a direction variable that encodes the choice
273 between up and down (or left and right). Here you see two chords,
274 with accents and arpeggios. In the first chord, the graphical objects
275 have all directions down (or left). The second chord has all
276 directions up (right).
278 @lilypond[quote,ragged-right]
280 \override SpacingSpanner #'spacing-increment = #3
281 \override TimeSignature #'transparent = ##t
283 \stemDown <e g b>4_>-\arpeggio
284 \override Arpeggio #'direction = #RIGHT
285 \stemUp <e g b>4^>-\arpeggio
290 The process of formatting a score consists of reading and writing the
291 variables of graphical objects. Some variables have a preset value. For
292 example, the thickness of many lines -- a characteristic of typographical
293 style -- is a variable with a preset value. You are free to alter this
294 value, giving your score a different typographical impression.
296 @lilypond[quote,ragged-right]
299 c'4-~ c'16 as g f e16 g bes c' des'4
304 \override Beam #'thickness = #0.3
305 \override Stem #'thickness = #0.5
306 \override Bar #'thickness = #3.6
307 \override Tie #'thickness = #2.2
308 \override StaffSymbol #'thickness = #3.0
309 \override Tie #'extra-offset = #'(0 . 0.3)
315 Formatting rules are also preset variables: each object has variables
316 containing procedures. These procedures perform the actual
317 formatting, and by substituting different ones, we can change the
318 appearance of objects. In the following example, the rule which note
319 head objects are used to produce their symbol is changed during the
322 @lilypond[quote,ragged-right]
323 #(set-global-staff-size 30)
325 #(define (mc-squared grob orig current)
326 (let* ((interfaces (ly:grob-interfaces grob))
327 (pos (ly:grob-property grob 'staff-position)))
328 (if (memq 'note-head-interface interfaces)
330 (ly:grob-set-property! grob 'stencil ly:text-interface::print)
331 (ly:grob-set-property! grob 'font-family 'roman)
332 (ly:grob-set-property! grob 'text
333 (make-raise-markup -0.5
335 ((-5) (make-simple-markup "m"))
336 ((-3) (make-simple-markup "c "))
337 ((-2) (make-smaller-markup (make-bold-markup "2")))
338 (else (make-simple-markup "bla")))))))))
340 \new Voice \relative c' {
342 \set autoBeaming = ##f
345 \once \override NoteHead #'stencil = #ly:note-head::brew-ez-stencil
346 \once \override NoteHead #'font-size = #-7
347 \once \override NoteHead #'font-family = #'sans
348 \once \override NoteHead #'font-series = #'bold
350 \once \override NoteHead #'style = #'cross
352 \applyOutput #'Voice #mc-squared
355 { d8[ es-( fis^^ g] fis2-) }
356 \repeat unfold 5 { \applyOutput #'Voice #mc-squared s8 }
363 @node What symbols to engrave?
364 @section What symbols to engrave?
369 The formatting process decides where to place symbols. However, this
370 can only be done once it is decided @emph{what} symbols should be
371 printed, in other words what notation to use.
373 Common music notation is a system of recording music that has evolved
374 over the past 1000 years. The form that is now in common use dates
375 from the early renaissance. Although the basic form (i.e., note heads
376 on a 5-line staff) has not changed, the details still evolve to
377 express the innovations of contemporary notation. Hence, it
378 encompasses some 500 years of music. Its applications range from
379 monophonic melodies to monstrous counterpoints for large orchestras.
381 How can we get a grip on such a many-headed beast, and force it into
382 the confines of a computer program? Our solution is to break up the
383 problem of notation (as opposed to engraving, i.e., typography) into
384 digestible and programmable chunks: every type of symbol is handled by
385 a separate module, a so-called plug-in. Each plug-in is completely
386 modular and independent, so each can be developed and improved
387 separately. Such plug-ins are called @code{engraver}s, by analogy
388 with craftsmen who translate musical ideas to graphic symbols.
390 In the following example, we see how we start out with a plug-in for
391 note heads, the @code{Note_heads_engraver}.
393 @lilypond[quote,ragged-right]
394 \include "engraver-example.ily"
401 \remove "Stem_engraver"
402 \remove "Phrasing_slur_engraver"
403 \remove "Slur_engraver"
404 \remove "Script_engraver"
405 \remove "Beam_engraver"
406 \remove "Auto_beam_engraver"
410 \remove "Accidental_engraver"
411 \remove "Key_engraver"
412 \remove "Clef_engraver"
413 \remove "Bar_engraver"
414 \remove "Time_signature_engraver"
415 \remove "Staff_symbol_engraver"
416 \consists "Pitch_squash_engraver"
423 Then a @code{Staff_symbol_engraver} adds the staff
425 @lilypond[quote,ragged-right]
426 \include "engraver-example.ily"
433 \remove "Stem_engraver"
434 \remove "Phrasing_slur_engraver"
435 \remove "Slur_engraver"
436 \remove "Script_engraver"
437 \remove "Beam_engraver"
438 \remove "Auto_beam_engraver"
442 \remove "Accidental_engraver"
443 \remove "Key_engraver"
444 \remove "Clef_engraver"
445 \remove "Bar_engraver"
446 \consists "Pitch_squash_engraver"
447 \remove "Time_signature_engraver"
454 the @code{Clef_engraver} defines a reference point for the staff
456 @lilypond[quote,ragged-right]
457 \include "engraver-example.ily"
464 \remove "Stem_engraver"
465 \remove "Phrasing_slur_engraver"
466 \remove "Slur_engraver"
467 \remove "Script_engraver"
468 \remove "Beam_engraver"
469 \remove "Auto_beam_engraver"
473 \remove "Accidental_engraver"
474 \remove "Key_engraver"
475 \remove "Bar_engraver"
476 \remove "Time_signature_engraver"
483 and the @code{Stem_engraver} adds stems.
485 @lilypond[quote,ragged-right]
486 \include "engraver-example.ily"
493 \remove "Phrasing_slur_engraver"
494 \remove "Slur_engraver"
495 \remove "Script_engraver"
496 \remove "Beam_engraver"
497 \remove "Auto_beam_engraver"
501 \remove "Accidental_engraver"
502 \remove "Key_engraver"
503 \remove "Bar_engraver"
504 \remove "Time_signature_engraver"
511 The @code{Stem_engraver} is notified of any note head coming along.
512 Every time one (or more, for a chord) note head is seen, a stem
513 object is created and connected to the note head. By adding
514 engravers for beams, slurs, accents, accidentals, bar lines,
515 time signature, and key signature, we get a complete piece of
518 @lilypond[quote,ragged-right]
519 \include "engraver-example.ily"
523 This system works well for monophonic music, but what about
524 polyphony? In polyphonic notation, many voices can share a staff.
526 @lilypond[quote,ragged-right]
527 \include "engraver-example.ily"
528 \new Staff << \topVoice \\ \botVoice >>
531 In this situation, the accidentals and staff are shared, but the stems,
532 slurs, beams, etc., are private to each voice. Hence, engravers should
533 be grouped. The engravers for note heads, stems, slurs, etc., go into a
534 group called @q{Voice context,} while the engravers for key, accidental,
535 bar, etc., go into a group called @q{Staff context.} In the case of
536 polyphony, a single Staff context contains more than one Voice context.
537 Similarly, multiple Staff contexts can be put into a single Score
538 context. The Score context is the top level notation context.
542 Internals Reference: @internalsref{Contexts}.
544 @lilypond[quote,ragged-right]
545 \include "engraver-example.ily"
548 \new Staff << \topVoice \\ \botVoice >>
549 \new Staff << \pah \\ \hoom >>
554 @node Music representation
555 @section Music representation
557 Ideally, the input format for any high-level formatting system is an
558 abstract description of the content. In this case, that would be the
559 music itself. This poses a formidable problem: how can we define what
560 music really is? Instead of trying to find an answer, we have reversed
561 the question. We write a program capable of producing sheet music,
562 and adjust the format to be as lean as possible. When the format can
563 no longer be trimmed down, by definition we are left with content
564 itself. Our program serves as a formal definition of a music
567 The syntax is also the user-interface for LilyPond, hence it is easy
577 a quarter note C1 (middle C) and an eighth note D1 (D above middle C)
585 On a microscopic scale, such syntax is easy to use. On a larger
586 scale, syntax also needs structure. How else can you enter complex
587 pieces like symphonies and operas? The structure is formed by the
588 concept of music expressions: by combining small fragments of music
589 into larger ones, more complex music can be expressed. For example
591 @lilypond[quote,verbatim,fragment,relative=1]
596 Chords can be constructed with @code{<<} and @code{>>} enclosing the notes
598 @c < > is not a music expression,
599 @c so we use <<>> iso. <> to drive home the point of
600 @c expressions. Don't change this back --hwn.
605 @lilypond[quote,fragment,relative=1]
606 \new Voice { <<c4 d4 e>> }
610 This expression is put in sequence by enclosing it in curly braces
611 @code{@{@tie{}@dots{}@tie{}@}}
614 @{ f4 <<c4 d4 e4>> @}
617 @lilypond[quote,relative=1,fragment]
622 The above is also an expression, and so it may be combined
623 again with another simultaneous expression (a half note) using <<,
627 << g2 \\ @{ f4 <<c4 d4 e4>> @} >>
630 @lilypond[quote,fragment,relative=2]
631 \new Voice { << g2 \\ { f4 <<c d e>> } >> }
634 Such recursive structures can be specified neatly and formally in a
635 context-free grammar. The parsing code is also generated from this
636 grammar. In other words, the syntax of LilyPond is clearly and
637 unambiguously defined.
639 User-interfaces and syntax are what people see and deal with
640 most. They are partly a matter of taste, and also subject of much
641 discussion. Although discussions on taste do have their merit, they
642 are not very productive. In the larger picture of LilyPond, the
643 importance of input syntax is small: inventing neat syntax is easy, while
644 writing decent formatting code is much harder. This is also
645 illustrated by the line-counts for the respective components: parsing
646 and representation take up less than 10% of the source code.
649 @node Example applications
650 @section Example applications
652 We have written LilyPond as an experiment of how to condense the art
653 of music engraving into a computer program. Thanks to all that hard
654 work, the program can now be used to perform useful tasks. The
655 simplest application is printing notes.
657 @lilypond[quote,relative=1]
665 By adding chord names and lyrics we obtain a lead sheet.
667 @lilypond[quote,ragged-right]
669 \chords { c2 c f2 c }
670 \new Staff \relative c' { \time 2/4 c4 c g'4 g a4 a g2 }
671 \new Lyrics \lyricmode { twin4 kle twin kle lit tle star2 }
675 Polyphonic notation and piano music can also be printed. The following
676 example combines some more exotic constructs.
678 @lilypondfile[quote,ragged-right]{screech-boink.ly}
680 The fragments shown above have all been written by hand, but that is
681 not a requirement. Since the formatting engine is mostly automatic, it
682 can serve as an output means for other programs that manipulate
683 music. For example, it can also be used to convert databases of
684 musical fragments to images for use on websites and multimedia
687 This manual also shows an application: the input format is text, and
688 can therefore be easily embedded in other text-based formats such as
689 @LaTeX{}, HTML, or in the case of this manual, Texinfo. By means of a
690 special program, the input fragments can be replaced by music images
691 in the resulting PDF or HTML output files. This makes it easy
692 to mix music and text in documents.
696 @node About this manual
697 @section About this manual
699 FIXME: needs almost-complete rewrite. -gp
701 There are four manuals about LilyPond: the @emph{Learning Manual},
702 the @emph{Notation Reference}, the @emph{Application Usage}, and the
703 @emph{Internals Reference}.
706 @subheading Learning Manual (LM)
708 This book explains how to begin learning LilyPond, as well as explaining
709 some key concepts in easy terms. It is recommended to read these
710 chapters in a linear fashion.
718 @emph{@ref{Tutorial}},
719 gives a gentle introduction to typesetting music. First time
720 users should start here.
723 @emph{@ref{Fundamental concepts}},
724 explains some general concepts about the lilypond file format. If
725 you are not certain where to place a command, read this chapter!
728 @emph{@ref{Working on LilyPond projects}},
729 discusses practical uses of LilyPond and how to avoid some common
733 @emph{@ref{Tweaking output}},
734 shows how to change the default engraving that LilyPond
740 @subheading Notation Reference (NR)
742 This book explains all the LilyPond commands which produce notation. It
743 assumes that readers are familiar with the concepts in the Learning
746 All of this needs to be rewritten after GDP, anyway.
753 @emph{@r ef{Basic notation}},
754 discusses topics grouped by notation construct. This section gives
755 details about basic notation that will be useful in almost any
759 @emph{@r ef{Instrument-specific notation}},
760 discusses topics grouped by notation construct. This section gives
761 details about special notation that will only be useful for particular
762 instrument (or vocal) groups.
765 @emph{@r ef{Advanced notation}},
766 discusses topics grouped by notation construct. This section gives
767 details about complicated or unusual notation.
770 @emph{@r ef{Changing defaults}},
771 explains how to fine tune layout.
774 @emph{@r ef{Non-musical notation}},
775 discusses non-musical output such as titles, multiple movements,
776 and how to select which MIDI instruments to use.
779 @emph{@r ef{Spacing issues}},
780 discusses issues which affect the global output, such as selecting
781 paper size or specifying page breaks.
784 @emph{@r ef{Interfaces for programmers}},
785 explains how to create music functions.
790 @subsubheading Appendices
792 This book contains useful reference charts.
799 @emph{@r ef{Literature list}},
800 contains a set of useful reference books for those who wish to know
801 more on notation and engraving.
805 @emph{@r ef{Scheme tutorial}},
806 presents a short introduction to Scheme, the programming
807 language that music functions use.
810 @emph{@r ef{Notation manual tables}},
811 are a set of tables showing the chord names, MIDI instruments,
812 a list of color names, and the Feta font.
815 @emph{@r ef{Templates}},
816 of LilyPond pieces. Just cut and paste a
817 template into a file, add notes, and you're done!
821 @emph{@r ef{Cheat sheet}},
822 is a handy reference of the most common LilyPond commands.
826 @emph{@r ef{LilyPond command index}},
827 is an index of all LilyPond @code{\commands}.
831 @emph{@r ef{LilyPond index}},
838 @subheading Program usage
840 This book explains how to execute the program and how to integrate
841 LilyPond notation with other programs.
846 @emph{@rprogram{Install}},
847 explains how to install LilyPond (including compilation if desired).
850 @emph{@rprogram{Setup}},
851 describes how to configure your computer for optimum LilyPond usage,
852 such as using special environments for certain text editors.
855 @emph{@rprogram{Running LilyPond}},
856 shows how to run LilyPond and its helper programs. In addition, this
857 section explains how to upgrade input files from previous versions of
861 @emph{@rprogram{LilyPond-book}},
862 explains the details behind creating
863 documents with in-line music examples, like this manual.
866 @emph{@rprogram{Converting from other formats}},
867 explains how to run the conversion programs. These programs are
868 supplied with the LilyPond package, and convert a variety of music
869 formats to the @code{.ly} format.
875 @subsubheading Other information
877 There are a number of other places which may be very valuable.
883 @cindex foreign languages
887 The @ref{Top,Music glossary,,music-glossary}, explains musical terms and
888 includes translations to various languages. It is also available in
892 The music glossary explains musical terms, and includes translations
893 to various languages. It is a separate document, available in HTML
896 If you are not familiar with music notation or music terminology
897 (especially if you are a non-native English speaker), it is highly
898 advisable to consult the glossary.
905 @uref{source/input/lsr/snippets/index.html,Snippets}
910 are a great collection of short examples which demonstrate tricks, tips,
911 and special features of LilyPond. Most of these snippets can also be
912 found in the @uref{http://lsr.dsi.unimi.it/,LilyPond Snippet
913 Repository}. This website also has a searchable LilyPond manual.
922 @ref{Top,Internals Reference,,lilypond-internals}
924 is a set of heavily cross linked HTML pages, which document the
925 nitty-gritty details of each and every LilyPond class, object, and
926 function. It is produced directly from the formatting definitions used.
928 Almost all formatting functionality that is used internally, is
929 available directly to the user. For example, all variables that control
930 thickness values, distances, etc., can be changed in input files. There
931 are a huge number of formatting options, and all of them are described
932 in this document. Each section of the notation manual has a @b{See
933 also} subsection, which refers to the generated documentation. In the
934 HTML document, these subsections have clickable links.
939 Once you are an experienced user, you can use the manual as reference:
940 there is an extensive index@footnote{If you are looking for something,
941 and you cannot find it in the manual, that is considered a bug. In
942 that case, please file a bug report.}, but the document is also
948 @uref{source/Documentation/user/lilypond-big-page.html, one big page},
950 which can be searched easily using the search facility of a web
954 In all HTML documents that have music fragments embedded, the LilyPond
955 input that was used to produce that image can be viewed by clicking
958 The location of the documentation files that are mentioned here can vary
959 from system to system. On occasion, this manual refers to
960 initialization and example files. Throughout this manual, we refer to
961 input files relative to the top-directory of the source archive. For
962 example, @file{input/@/lsr/@/dirname/@/bla@/.ly} may refer to the file
963 @file{lilypond@/2.x.y/@/input/@/lsr/@/dirname/@/bla@/.ly}. On binary
964 packages for the Unix platform, the documentation and examples can
965 typically be found somewhere below
966 @file{/usr/@/share/@/doc/@/lilypond/}. Initialization files, for
967 example @file{scm/@/lily@/.scm}, or @file{ly/@/engraver@/-init@/.ly},
968 are usually found in the directory @file{/usr/@/share/@/lilypond/}.
970 @cindex adjusting output
973 @cindex lilypond-internals
974 @cindex internal documentation
976 @cindex extending lilypond
979 Finally, this and all other manuals, are available online both as PDF
980 files and HTML from the web site, which can be found at
981 @uref{http://@/www@/.lilypond@/.org/}.