Engraving symmetric or palindromical music - Revision history

Lemzwerg: New category

2025-11-21T23:24:41Z

New category

← Older revision		Revision as of 23:24, 21 November 2025
Line 94:		Line 94:
	[[Category:Scheme]]		[[Category:Scheme]]
	[[Category:Contemporary notation]]		[[Category:Contemporary notation]]
	[[Category:Really cool]][[Category:Snippet]]		[[Category:Really cool]]
			[[Category:Snippet]]

Lemzwerg at 22:52, 21 November 2025

2025-11-21T22:52:23Z

← Older revision		Revision as of 22:52, 21 November 2025
Line 94:		Line 94:
	[[Category:Scheme]]		[[Category:Scheme]]
	[[Category:Contemporary notation]]		[[Category:Contemporary notation]]
	[[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

2025-11-16T18:48:49Z

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 18:48, 16 November 2025
Line 1:		Line 1:
	Symmetric, or palindromical music can be produced, first, by printing some music, and second, by printing the same music applying a Scheme function to reverse the syntax.		Symmetric, or palindromical music can be produced, first, by printing some music, and second, by printing the same music applying a Scheme function to reverse the syntax.

	<lilypond version="2.24.0">		<lilypond version="2.24">
	%% http://lsr.di.unimi.it/LSR/Item?id=130		%% http://lsr.di.unimi.it/LSR/Item?id=130
	%% see also http://lilypond.1069038.n5.nabble.com/LSR-v-2-18-quot-Engraving-symmetric-or-palindromical-music-quot-works-partially-tc159398.html		%% see also http://lilypond.1069038.n5.nabble.com/LSR-v-2-18-quot-Engraving-symmetric-or-palindromical-music-quot-works-partially-tc159398.html

Jean Abou Samra: Import snippet from LSR

2025-10-26T22:36:01Z

Import snippet from LSR

New page

Symmetric, or palindromical music can be produced, first, by printing some music, and second, by printing the same music applying a Scheme function to reverse the syntax.

<lilypond version="2.24.0">
%% http://lsr.di.unimi.it/LSR/Item?id=130
%% see also http://lilypond.1069038.n5.nabble.com/LSR-v-2-18-quot-Engraving-symmetric-or-palindromical-music-quot-works-partially-tc159398.html

% provided by harm on Feb. 2014
% partially new coding to reflect the changes to 'EventChord, introduced after 2.14.

#(define (turn-span-dir music)
(let ((span-dir (ly:music-property music 'span-direction)))
(if (ly:dir? span-dir)
(ly:music-set-property! music 'span-direction (- span-dir))
(music-map
(lambda (mus)
(if (music-is-of-type? mus 'note-event)
(begin
(for-each
(lambda (m)
(if (music-is-of-type? m 'span-event)
(ly:music-set-property! m 'span-direction
(- (ly:music-property m 'span-direction)))
m))
(ly:music-property mus 'articulations))
mus)
mus))
music))))

#(define (reverse-music music)
(let* ((elements (ly:music-property music 'elements))
(reversed (reverse elements))
(e (ly:music-property music 'element)))

(if (not (null? elements))
(ly:music-set-property! music 'elements reversed))

(if (ly:music? e)
(ly:music-set-property!
music 'element
(reverse-music e)))

(turn-span-dir music)

(map reverse-music reversed)

music))

reverseMusic =
#(define-music-function (m) (ly:music?)
(reverse-music m))

music =
\relative c'' { c4-.\(\cresc\startTrillSpan <d f>4--( e4\startTextSpan f4 }

\score {
\context Voice {
\music
\reverseMusic \music
}
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% above one simply uses event-chord-wrap!
%{

#(define (reverse-music music)
(let* ((elements (ly:music-property music 'elements))
(reversed (reverse elements))
(e (ly:music-property music 'element))
(span-dir (ly:music-property music 'span-direction)))

(ly:music-set-property! music 'elements reversed)

(if (ly:music? e)
(ly:music-set-property!
music 'element
(reverse-music e)))

(if (ly:dir? span-dir)
(ly:music-set-property! music 'span-direction (- span-dir)))

(map reverse-music reversed)

music))

reverseMusic =
#(define-music-function (m) (ly:music?)
(reverse-music (event-chord-wrap! m)))

%}
</lilypond>

[[Category:Scheme]]
[[Category:Scheme]]
[[Category:Contemporary notation]]
[[Category:Really cool]]