Lemzwerg: New category

2025-11-21T23:33:51Z

New category

← Older revision		Revision as of 23:33, 21 November 2025
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	[[Category:Scheme]]		[[Category:Scheme]]
	[[Category:Preparing parts]]		[[Category:Preparing parts]]
	[[Category:Really cool]][[Category:Snippet]]		[[Category:Really cool]]
			[[Category:Snippet]]

Lemzwerg at 22:52, 21 November 2025

2025-11-21T22:52:43Z

← Older revision		Revision as of 22:52, 21 November 2025
Line 165:		Line 165:
	[[Category:Scheme]]		[[Category:Scheme]]
	[[Category:Preparing parts]]		[[Category:Preparing parts]]
	[[Category:Really cool]]		[[Category:Really cool]][[Category:Snippet]]

Jean Abou Samra: Replace version="2.24.0" with version="2.24" now that the LilyWiki extension supports auto-selecting the latest release in a stable series

2025-11-16T18:53:03Z

Replace version="2.24.0" with version="2.24" now that the LilyWiki extension supports auto-selecting the latest release in a stable series

← Older revision		Revision as of 18:53, 16 November 2025
Line 12:		Line 12:
	A full and updated version of <code>\extractMusic</code> can be found [http://gillesth.free.fr/Lilypond/extractMusic/ here]. There are some additional useful features and other enhancement functions on that page, with a description of each of them in a small document (in pdf format) with multiple voices, <code>\repeat</code> structures etc.		A full and updated version of <code>\extractMusic</code> can be found [http://gillesth.free.fr/Lilypond/extractMusic/ here]. There are some additional useful features and other enhancement functions on that page, with a description of each of them in a small document (in pdf format) with multiple voices, <code>\repeat</code> structures etc.

	<lilypond version="2.24.0">		<lilypond version="2.24">
	%% http://lsr.di.unimi.it/LSR/Item?id=542		%% http://lsr.di.unimi.it/LSR/Item?id=542

Jean Abou Samra: Import snippet from LSR

2025-10-26T22:39:31Z

Import snippet from LSR

New page

This snippet provides an <code>\extractMusic</code> function that can be used as follows:

<blockquote><code>\extractMusic music from during</code></blockquote>
For example, in the second Staff of the score below, the following has been used :

<blockquote><code>\extractMusic \music s1 s1*2</code></blockquote>
This has kept the music beginning after the first measure (i.e., at the second measure) for two measures.<br />
All data (notes, scripts, dynamics and various <code>\override</code>s) outside this range have been deleted.

Note that this function should also work with multiple voices, <code>\repeat</code> structures etc.

A full and updated version of <code>\extractMusic</code> can be found [http://gillesth.free.fr/Lilypond/extractMusic/ here]. There are some additional useful features and other enhancement functions on that page, with a description of each of them in a small document (in pdf format) with multiple voices, <code>\repeat</code> structures etc.

<lilypond version="2.24.0">
%% http://lsr.di.unimi.it/LSR/Item?id=542

#(use-modules (srfi srfi-39))

#(define *current-moment* (make-parameter (ly:make-moment 0/1 0/1)))

#(define moment-null (ly:make-moment 0/1 0/1))

#(define (music-has-no-length? music)
"Is music empty of notes, rests or skips?"
(equal? (ly:music-length music) moment-null))

#(define (simultaneous? music)
(memq (ly:music-property music 'name)
(list 'SimultaneousMusic 'EventChord)))

#(define (defined-music? music)
(not (eq? 'Music (ly:music-property music 'name))))

#(define (chord-event? music)
(eq? 'EventChord (ly:music-property music 'name)))

#(define (get-duration music)
(ly:music-property music 'duration))

#(define (moment>=? momentA momentB)
(not (ly:moment<? momentA momentB)))

#(define (moment-inside? moment from-moment to-moment)
(and
(moment>=? moment from-moment)
(ly:moment<? moment to-moment)))

#(define (whole-music-inside? begin-music end-music left-range right-range)
(and
(moment>=? begin-music left-range)
(moment>=? right-range end-music )
(not (equal? begin-music right-range))))

#(define (whole-music-outside? begin-music end-music left-range right-range)
(or
(moment>=? left-range end-music)
(moment>=? begin-music right-range)))

#(define (moment->duration moment)
;see duration.cc in Lilypond sources (Duration::Duration)
(let* ((p (ly:moment-main-numerator moment))
(q (ly:moment-main-denominator moment))
(k (- (ly:intlog2 q) (ly:intlog2 p)))
(dots 0))
;(ash p k) = p * 2^k
(if (< (ash p k) q) (set! k (1+ k)))
(set! p (- (ash p k) q))
(while (begin (set! p (ash p 1))(>= p q))
(set! p (- p q))
(set! dots (1+ dots)))
(if (> k 6)
(ly:make-duration 6 0)
(ly:make-duration k dots))
))

#(define (extract-music music from to)
"Keeps only music between `from' and `to', `from' and `to' as moment"
(let ((begin-pos (*current-moment*))
(end-pos (ly:moment-add
(*current-moment*)
(ly:music-length music))))
(cond
((whole-music-inside? begin-pos end-pos from to)
(*current-moment* end-pos)
music)
((whole-music-outside? begin-pos end-pos from to)
(*current-moment* end-pos)
(make-music 'Music))
; the intervals [begin-pos end-pos] [from to] overlap
(else
(cond
; inside a chords or for multiRest events
((ly:duration? (get-duration music))
(if (moment-inside? begin-pos from to)
(set! end-pos to)
(begin
(set! begin-pos from)
(if (not (moment-inside? end-pos from to))(set! end-pos to))))
(ly:music-set-property! music 'duration
(moment->duration (ly:moment-sub end-pos begin-pos)))
(*current-moment* end-pos)
music)
(else ; for containers of chords
(let ((elts (ly:music-property music 'elements))
(elt (ly:music-property music 'element)))
(if (ly:music? elt)
(ly:music-set-property! music 'element (extract-music elt from to)))
(if (pair? elts)
(cond
((simultaneous? music) ; simultaneous music OR EventChords
(ly:music-set-property! music 'elements (filter
(lambda (evt)
(or (music-has-no-length? evt) ; i.e for 'VoiceSeparator
(begin
(*current-moment* begin-pos) ; restore *current-moment*
(set! evt (extract-music evt from to))
(defined-music? evt)))) ; keeps if not (make-music 'Music)
elts))
(*current-moment* end-pos))
(else ; sequential music
(ly:music-set-property! music 'elements (filter
(lambda (evt)
(set! evt (extract-music evt from to))
(defined-music? evt))
elts)))))
music)))))))

%%%%%%%%%%%%%%%%%%%%%% the main function %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
extractMusic =
#(define-music-function (music from during) (ly:music? ly:music? ly:music?)
(let* ((from-length (ly:music-length from))
(during-length (ly:music-length during))
(to-length (ly:moment-add during-length from-length)))
(parameterize ((*current-moment* (ly:make-moment 0/1 0/1)))
(extract-music music from-length to-length))))
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

music = \relative c' {
\override Staff.NoteHead.color = #blue
<c e>4-- d\< \tuplet 3/2 { e8 f g } a8^"a text" c\!
b8 c b a^"another text" << { g4 f8 e } \\ { e4 d8 c } >>
\override Voice.NoteHead.color = #green
d2 g
\override Voice.NoteHead.color = #red
g16 a g f e8 d c2
}

\score {
<<
\new Staff \new Voice {
\music
c'1
}
\new Staff \new Voice {
s1
\extractMusic \music s1 s1*2
s1
c'1
}
>>
}
</lilypond>

[[Category:Scheme]]
[[Category:Preparing parts]]
[[Category:Really cool]]

Extracting unmodified fragments of a music expression - Revision history

Lemzwerg: New category

Lemzwerg at 22:52, 21 November 2025

Jean Abou Samra: Replace version="2.24.0" with version="2.24" now that the LilyWiki extension supports auto-selecting the latest release in a stable series

Jean Abou Samra: Import snippet from LSR