8 The art of music typography is called @emph{(plate) engraving}. The
9 term derives from the traditional process of music printing. Only a
10 few decades ago, sheet music was made by cutting and stamping the
11 music into zinc or pewter plates in mirror image. The plate would be
12 inked, and the depressions caused by the cutting and stamping would
13 hold ink. An image was formed by pressing paper to the plate. The
14 stamping and cutting was completely done by hand. Making corrections
15 was cumbersome, so engraving had to be done correctly in one go. Of
16 course, this was a highly specialized skill, and a craftsman had to
17 complete around 10 years of practical training before he could be a
21 Nowadays, all newly printed music is produced on computers. This has
22 obvious advantages: prints are cheaper to make, and editorial work can
23 be done over e-mail. Unfortunately, the pervasive use of computers has
24 also decreased the graphical quality of scores. Computer printouts
25 have a bland, mechanical look, which makes them unpleasant to play
28 The images below illustrate the difference between traditional
29 engraving, typical computer output, and how LilyPond mimicks the
30 traditional look. The left picture shows a scan of a flat symbol from
31 a Henle edition published in 2000. In the center show symbol from a
32 hand engraved B@"{a}renreiter edition of the same music. The left scan
33 illustrates typical flaws of computer print: the staff line are thin,
34 the weight of the symbol matches the light lines, and the glyph has a
35 straight layout with sharp corners. By contrast, the B@"{a}renreiter
36 has a bold and almost voluptuous rounded look. Our flat symbol is
37 designed after, among others, this one. It is rounded, and its weight
38 harmonizes with the thickness of our staff lines, which are also much
39 thicker than Henle's lines.
41 @multitable @columnfractions .1 .3 .3 .3
44 @image{henle-flat-bw,4cm}
47 <img src=henle-flat-bw.png>
52 @image{baer-flat-bw,4cm}
55 <img src=baer-flat-bw.png>
60 @image{lily-flat-bw,4cm}
63 <img src=lily-flat-bw.png>
69 B@"{a}renreiter (1950)
71 LilyPond Feta font (2003)
76 @cindex musical symbols
81 In spacing, the distribution of space should reflect the durations
82 between notes. However, many modern scores adhere to the durations
83 with mathematical precision, and that leads to a poor result. In the
84 next example, a motive is printed twice. It is printed using exact
85 mathematical spacing, and with some corrections. Can you spot which
88 @cindex optical spacing
91 \override Staff.NoteSpacing #'stem-spacing-correction
94 \stemDown b'4 e''4 a'4 e''4| \stemBoth
96 \override Staff.NoteSpacing #'stem-spacing-correction
98 \override Staff.StaffSpacing #'stem-spacing-correction
101 \stemDown b'4 e''4 a'4 e''4|
103 \paper { raggedright = ##t } }
106 @cindex regular rhythms
107 @cindex regular spacing
109 The fragment only uses quarter notes: notes that are played in a
110 constant rhythm. The spacing should reflect that. Unfortunately, the
111 eye deceives us a little: not only does it notice the distance between
112 note heads, it also takes into account the distance between
113 consecutive stems. As a result, the notes of an up-stem/down-stem
114 combination should be put farther apart, and the notes of a down-up
115 combination should be put closer together, all depending on the
116 combined vertical positions of the notes. The first two measures are
117 printed with this correction, the last two measures without. The notes
118 in the last two measures form down-stem/up-stem clumps of notes.
122 Musicians are usually more absorbed with performing the music than
123 with studying its looks, so this nitpicking about typographical
124 details may seem academical. That is not justified. In larger pieces
125 with monotonous rhythms, spacing corrections lead to subtle variations
126 in the layout of every line, giving each one a distinct visual
127 signature. Without this signature, all lines would look the same, they
128 become like a labyrinth. If the musician looks away once or has a
129 lapse in his concentration, he will be lost on the page.
131 Similarly, the strong visual look of bold symbols on heavy staff lines
132 stands out better when music is far away from reader, for example, if
133 it is on a music stand. A careful distribution of white space allows
134 music to be set very tightly without cluttering symbols together. The
135 result minimizes the number of page turns,
137 This is a common characteristic of typography. Layout should be
138 pretty, not only for its own sake, but especially because it helps the
139 reader in his task. For performance material like sheet music, this is
140 doubly important: musicians have a limited amount of attention. The
141 less attention they need for reading, the more they can focus on
142 playing itself. In other words, better typography translates to better
145 Hopefully, these examples also demonstrate that music typography is an
146 art that is subtle and complex, and to produce it requires
147 considerable expertise, which musicians usually do not have. LilyPond
148 is our effort to bring the graphical excellence of hand-engraved music
149 to the computer age, and make it available to normal musicians. We
150 have tuned our algorithms, font-designs, and program settings to
151 produce prints that match the quality of the old editions we love to
152 see and love to play from.
157 * Automated engraving::
158 * What symbols to engrave?::
159 * Music representation::
160 * Example applications::
161 * About this manual::
164 @node Automated engraving
165 @section Automated engraving
167 How do we go about implementing typography? If craftsmen need over
168 ten years to become true masters, how could we simple hackers ever
169 write a program to take over their jobs?
171 The answer is: we cannot. Typography relies on human judgement of
172 appearance, so people cannot be replaced ultimately. However, much of
173 the dull work can be automated. If LilyPond solves most of the common
174 situations correctly, then this will be a huge improvement over
175 existing software. The remaining cases can be tuned by hand. Over the
176 course of years, the software can be refined to do more and more
177 automatically, so manual overrides are less and less necessary.
179 When we started, we wrote the program in C++. With this design, the
180 program functionality was set in stone stone by us developers. That
181 proved to be unsatisfactory:
185 @item When LilyPond makes mistakes,
186 users need to override formatting decisions. Therefore, the user
187 must access to the formatting engine. Hence, rules and settings cannot
188 be fixed by us at compile time, but they must be accessible for users
191 @item Engraving is a matter of visual judgement, and therefore a matter of
192 taste. As knowledgeable as we are, users can disagree with our
193 personal decisions. Therefore, the definitions of typographical style
194 must also be accessible to the user.
196 @item Finally, we continually refine the formatting algorithms, so we
197 need a flexible approach to rules. The C++ language forces a certain
198 method of grouping rules that do not match well with how music
203 The formatting architecture of LilyPond addresses these needs. It is
204 built around the notion graphical objects, carrying variables. The
205 architecture encompasses formatting rules, typographical style and
206 individual formatting decisions.
208 Variables control layout decisions. For example, many objects have a
209 direction variable that encodes the choice between up and down (or
210 left and right). Here you see two chords, with accents and
211 arpeggio. In the first chord, the objects have all directions down (or
212 left). The second chord has all directions up (right).
214 @lilypond[raggedright,relative=1]
216 \override SpacingSpanner #'spacing-increment = #3
217 \override TimeSignature #'transparent = ##t
222 \override Arpeggio #'direction = #RIGHT
228 The process of formatting a score consists of reading and
229 writing object variables.
231 Some variables have a preset value. For example, the thickness of many
232 lines ---a characteristic of typographical style--are preset
233 variables. Changing them gives a different typographical impression:
238 c'4-~ c'16 as g f e16 g bes c' des'4
240 \paper { raggedright = ##t }
245 linethickness = 1.5 \pt
248 \override Beam #'thickness = #0.3
249 \override Stem #'thickness = #0.5
250 \override Bar #'thickness = #3.6
251 \override Tie #'thickness = #2.2
254 \override Tie #'extra-offset = #'(0 . 0.3)
259 Formatting rules are also preset variables: each object has variables
260 containing procedures. These procedure perform the actual formatting,
261 and by substituting different ones, we can change behavior. In the
262 following example, the rule that note head objects use to produce
263 their symbol is changed during the music fragment:
266 @lilypond[raggedright]
267 #(define (mc-squared gr org cur)
269 ((ifs (ly:grob-property gr 'interfaces))
270 (sp (ly:grob-property gr 'staff-position)) )
271 (if (and (memq 'note-head-interface ifs)
272 (memq sp '(-2 -3 -5)))
274 (ly:grob-set-property! gr 'print-function brew-new-markup-stencil)
275 (ly:grob-set-property! gr 'font-family 'roman)
276 (ly:grob-set-property!
278 (make-raise-markup -0.5
280 ((-5) (make-simple-markup "m"))
281 ((-3) (make-simple-markup "c "))
282 ((-2) (make-smaller-markup (make-bold-markup "2")))
283 (else (make-simple-markup "bla"))
288 \notes \context Voice \relative c'
291 \set autoBeaming = ##f
294 \once \override NoteHead #'print-function
295 = #Note_head::brew_ez_stencil
297 \once \override NoteHead #'style
300 \applyoutput #mc-squared
302 << { d8[ es-( fis^^ g] fis2-) }
303 \repeat unfold 5 { \applyoutput #mc-squared s8 } >>
313 @node What symbols to engrave?
314 @section What symbols to engrave?
319 The formatting process in LilyPond decides where to place
320 symbols. However, this can only be done once it is decided @emph{what}
321 symbols should be printed, in other words what notation to use.
323 Common music notation is a system of recording music that has evolved
324 over the past 1000 years. The form that is now in common use, dates
325 from the early renaissance. Although, the basic form (i.e. note heads on a
326 5-line staff) has not changed, the details still change to express the
327 innovations of contemporary notation. Hence, it encompasses some 500
328 years of music. Its applications range from monophonic melodies to
329 monstrous counterpoint for large orchestras.
331 How can we get a grip on such a many-headed beast, and force it into
332 the confines of a computer program? We have broken up the problem of
333 notation (as opposed to engraving, i.e. typography) into digestible
334 and programmable chunks: every type of symbol is handled by a separate
335 module, a so-called plug-in. Each plug-in is completely modular and
336 independent, so each can be developed and improved separately. People
337 that translate musical ideas to graphic symbols are called copyists or
338 engravers, so by analogy, each plug-in is called @code{engraver}.
340 In the following example, we see how we start out with a plug-in for
341 note heads, the @code{Note_heads_engraver}.
344 \include "engraver-example.lyinc"
348 \translator { \VoiceContext
349 \remove "Stem_engraver"
350 \remove "Phrasing_slur_engraver"
351 \remove "Slur_engraver"
352 \remove "Script_engraver"
353 \remove "Beam_engraver"
354 \remove "Auto_beam_engraver"
357 \translator { \StaffContext
358 \remove "Accidental_engraver"
359 \remove "Key_engraver"
360 \remove "Clef_engraver"
361 \remove "Bar_engraver"
362 \remove "Time_signature_engraver"
363 \remove "Staff_symbol_engraver"
364 \consists "Pitch_squash_engraver"
371 Then a @code{Staff_symbol_engraver} adds the staff:
374 \include "engraver-example.lyinc"
378 \translator { \VoiceContext
379 \remove "Stem_engraver"
380 \remove "Phrasing_slur_engraver"
381 \remove "Slur_engraver"
382 \remove "Script_engraver"
383 \remove "Beam_engraver"
384 \remove "Auto_beam_engraver"
387 \translator { \StaffContext
388 \remove "Accidental_engraver"
389 \remove "Key_engraver"
390 \remove "Clef_engraver"
391 \remove "Bar_engraver"
392 \consists "Pitch_squash_engraver"
393 \remove "Time_signature_engraver"
400 The @code{Clef_engraver} defines a reference point for the staff:
403 \include "engraver-example.lyinc"
407 \translator { \VoiceContext
408 \remove "Stem_engraver"
409 \remove "Phrasing_slur_engraver"
410 \remove "Slur_engraver"
411 \remove "Script_engraver"
412 \remove "Beam_engraver"
413 \remove "Auto_beam_engraver"
415 \translator { \StaffContext
416 \remove "Accidental_engraver"
417 \remove "Key_engraver"
418 \remove "Bar_engraver"
419 \remove "Time_signature_engraver"
426 And the @code{Stem_engraver} adds stems:
429 \include "engraver-example.lyinc"
433 \translator { \VoiceContext
434 \remove "Phrasing_slur_engraver"
435 \remove "Slur_engraver"
436 \remove "Script_engraver"
437 \remove "Beam_engraver"
438 \remove "Auto_beam_engraver"
440 \translator { \StaffContext
441 \remove "Accidental_engraver"
442 \remove "Key_engraver"
443 \remove "Bar_engraver"
444 \remove "Time_signature_engraver"
450 The @code{Stem_engraver} is notified of any note head coming along.
451 Every time one (or more, for a chord) note head is seen, a stem
452 object is created and connected to the note head.
454 By adding engravers for beams, slurs, accents, accidentals, bar lines,
455 time signature, and key signature, we get a complete piece of
459 \include "engraver-example.lyinc"
466 This system works well for monophonic music, but what about
467 polyphony? In polyphonic notation, many voices can share a staff.
470 \include "engraver-example.lyinc"
471 \score { \context Staff << \topVoice \\ \botVoice >> }
474 In this situation, the accidentals and staff are shared, but the
475 stems, slurs, beams, etc. are private to each voice. Hence, engravers
476 should be grouped. The engravers for note heads, stems, slurs, etc. go
477 into a group called ``Voice context,'' while the engravers for key,
478 accidental, bar, etc. go into a group called ``Staff context.'' In the
479 case of polyphony, a single Staff context contains more than one Voice
480 context. In polyphonic notation, many voices can share a staff:
481 Similarly, more Staff contexts can be put into a single Score context.
484 \include "engraver-example.lyinc"
486 << \new Staff << \topVoice \\ \botVoice >>
487 \new Staff << \pah \\ \hoom >>
492 @node Music representation
493 @section Music representation
495 Ideally, the input format for any high-level formatting system is an
496 abstract description of the content. In this case, that would be the
497 music itself. This poses a formidable problem: how can we define what
498 music really is? Instead of trying to find an answer, we have reversed
499 the question. We write a program capable of producing sheet music,
500 and adjust the format to be as lean as possible. When the format can
501 no longer be trimmed down, by definition we are left with content
502 itself. Our program serves as a formal definition of a music
506 The syntax is also the user-interface for LilyPond, hence it is easily typable, e.g.,
510 Are a quarter note C (the central C) and eighth note D1 (the D above
511 central C), as in this example:
517 On a microscopic scale, such syntax is easy to use. On a larger scale,
518 syntax also needs structure. How else can you enter complex pieces
519 like symphonies and operas? The structure is formed by the concept of
520 music expressions: by combining small fragments of music into larger
521 ones, more complex music can be expressed. For example,
523 @lilypond[verbatim,fragment]
527 Combine this simultaneously with two other notes by enclosing in << and >>.
530 @lilypond[verbatim,fragment]
536 This expression is put in sequence by enclosing it in braces, i.e.,
543 \new Voice { <<c4 d4 e4>> f4 }
546 The above is another expression, and therefore, it many combined again
547 with a simultaneous expression (in this case, a half note).
550 << { <<c4 d4 e4>> f4 } g2 >>
553 << g2 \\ { <c d e>4 f4 } >>
557 Such recursive structures can be specified neatly and formally in a
558 context-free grammar. The parsing code is also generated from this
559 grammar. In other words, the syntax of LilyPond is clearly and
560 unambiguously defined.
562 User-interfaces and syntax are what people see and deal with
563 most. They are partly a matter of taste, and also subject of much
564 discussion. Although discussions on taste do have their merit, they
565 are not very productive. In the larger picture of LilyPond, the
566 importance of input syntax is small: inventing neat syntax is easy,
567 writing decent formatting code is much harder. This is also
568 illustrated by the line-counts for the respective components: parsing
569 and representation take up less than 10% of the code.
572 @node Example applications
573 @section Example applications
575 We have written LilyPond as an experiment of how to condense the art
576 of music engraving into a computer program. Thanks to all that hard
577 work, the program can now be used to perform useful tasks. The
578 simplest application is printing notes:
580 @lilypond[relative=1]
581 \time 2/4 c4 c g'4 g a4 a g2
584 By adding chord names and lyrics we obtain a lead sheet:
586 @lilypond[raggedright]
588 \context ChordNames \chords { c2 c f2 c }
589 \new Staff \notes \relative c' { \time 2/4 c4 c g'4 g a4 a g2 }
590 \context Lyrics \lyrics { twin4 kle twin kle lit tle star2 } >> }
593 Polyphonic notation and piano music can also be printed. The following
594 example combines some more exotic constructs:
596 @lilypondfile{screech-boink.ly}
598 The fragments shown above have all been written by hand, but that is
599 not a requirement. Since the formatting engine is mostly automatic, it
600 can serve as an output means for other programs that manipulate
601 music. For example, it can also be used to convert databases of
602 musical fragments to images for use on websites and multimedia
605 This manual also shows an application: the input format is plain text,
606 and can therefore be easily embedded in other text-based formats, such
607 as La@TeX{}, HTML or in the case of this manual, Texinfo. By means of a
608 special program, the input fragments can be replaced by music images in
609 the resulting PostScript or HTML output files. This makes it easy to
610 mix music and text in documents.
614 @node About this manual
615 @section About this manual
617 The manual is divided into the following chapters:
622 @emph{@ref{Tutorial}}
623 gives a gentle introduction to typesetting music.
624 First time users should start here.
629 @emph{@ref{Notation manual}}
630 discusses topics grouped by notation construct. Once you master the
631 basics, this is the place to look up details.
636 @emph{@ref{Literature list}}
637 contains a set of useful reference books, for those who wish to know
638 more on notation and engraving.
643 @emph{@ref{Technical manual}}
645 discusses the general design of the program, and how to extend its
651 @emph{@ref{Invoking LilyPond}} explains how to run LilyPond and its helper
658 @emph{@ref{lilypond-book manual}}
659 explains the details behind creating documents with in-line music
660 examples (like this manual).
667 @emph{@ref{Converting from other formats}}
668 explains how to run the conversion programs. These programs
669 are supplied with the LilyPond package, and convert a variety of music
670 formats to the @code{.ly} format. In addition, this section explains
671 how to upgrade input files from previous versions of LilyPond.
675 Once you are an experienced user, you can use the manual as reference:
676 there is an extensive index@footnote{If you are looking for something,
677 and you cannot find it in the manual, that is considered a bug. In
678 that case, please file a bug report.}, but the document is also
684 @uref{../lilypond.html, a big HTML page}
686 which can be searched easily using the search facility of a web
688 @cindex search in manual
689 @cindex using the manual
692 If you are not familiar with music notation or music terminology
693 (especially if you are a non-native English speaker), then it is
694 advisable to consult the glossary as well. The glossary explains
695 musical terms, and includes translations to various languages. It is a
697 @uref{../music-glossary.html,separate document}.
700 separate document, available in HTML and PDF.
705 @cindex foreign languages
709 This manual is not complete without a number of other documents. They
710 are not available in print, but should be included with the
711 documentation package for your platform:
717 (available @uref{../lilypond-internals/lilypond-internals.html,here})
720 The program reference is a set of heavily cross linked HTML pages,
721 which documents the nit-gritty details of each and every LilyPond
722 class, object and function. It is produced directly from the
723 formatting definitions used.
725 Almost all formatting functionality that is used internally, is
726 available directly to the user. For example, all variables that
727 control thicknesses, distances, etc, can be changed in input
728 files. There are a huge number of formatting options, and all of them
729 are described in the generated documentation. Each section of the
730 notation manual has a @b{See also} subsection, which refers to the
731 the generated documentation. In the HTML document, these subsections
732 have clickable links.
737 (available @uref{../../../input/template/out-www/collated-files.html,here})
740 After you have gone through the tutorial, you should be able to write
741 input files. In practice, writing files from scratch turns out to be
742 intimidating. To give you a head start, we have collected a number of
743 often-used formats in example files. These files can be used as a
744 start: simply copy the template, and add notes in the appropriate
748 Various input examples
750 (available @uref{../../../../input/test/out-www/collated-files.html,here})
754 These small files show various tips and tricks, and are available as a
755 big HTML document, with pictures and explanatory texts included.
761 (available @uref{../../../input/regression/out-www/collated-files.html,here})
764 This collection of files tests each notation and engraving feature of
765 LilyPond in one file. The collection is primarily there to help us
766 debug problems, but it can be instructive to see how we exercise the
767 program. The format is like the tips and tricks document.
772 In all HTML documents that have music fragments embedded, the LilyPond
773 input that was used to produce that image can be viewed by clicking
776 The location of the documentation files that are mentioned here can
777 vary from system to system. On occasion, this manual refers to
778 initialization and example files. Throughout this manual, we refer to
779 input files relative to the top-directory of the source archive. For
780 example, @file{input/test/bla.ly} may refer to the file
781 @file{lilypond-1.7.19/input/test/bla.ly}. On binary packages for the
782 Unix platform, the documentation and examples can typically be found
783 somewhere below @file{/usr/share/doc/lilypond/}. Initialization files,
784 for example @file{scm/lily.scm}, or @file{ly/engraver-init.ly}, are
785 usually found in the directory @file{/usr/share/lilypond/}.
787 @cindex adjusting output
790 @cindex lilypond-internals
791 @cindex internal documentation
793 @cindex extending lilypond
797 Finally, this and all other manuals, are available online both as PDF
798 files and HTML from the web site, which can be found at
799 @uref{http://www.lilypond.org/}.