David Kastrup <d...@gnu.org> writes:
> Eric <papa.e...@free.fr> writes:
>
>> Hi Lilypond helpers,
>>
>> The following snippet :
>>
>> http://lsr.dsi.unimi.it/LSR/Snippet?id=346
>>
>> does not work any longer.
>>
>> The error occurs "In procedure car in expression (car pes):
>> /home/eric/musique/lilypond/test.ly:49:49: Wrong type (expecting
>> pair): ()"
>>
>> that is, at line (in function defineTransform) :
>>
>> (pnew (ly:music-property (car pes) 'pitch))
>>
>>
>> Can anyone find what is wrong ?
>
> Things got simpler. Converge the two lines
>
> (pes (ly:music-property (list-ref pitches i)
> elements))
> (pnew (ly:music-property (car pes) 'pitch))
>
> into
>
> (pnew (ly:music-property (list-ref pitches i)
> pitch))
Actually, I find I like the following better (except one should likely
make the fold-some-music call into a separate predefined extract-pitches
function).
% This file demonstrates how to typeset different pitches with the
% same rhythm.
% It defines a function, defineTransform,
% that you can use to make transformation functions.
% Call it like this:
% myTransformation =
% \defineTransform { c'4 c'8 c'8 d'16 d' d' d' < c' d' > }
% You have now defined a transformation with the name "myTransformation".
% The rhythm in the transformation must be specified with notes c' d' e' f' g' etc.
% After having defined the transformation, you can call it like this:
% \myTransformation { e gis }
% To insert the rhythm from the transformation,
% where c' is substituted with e and d' is substituted with gis
%%% The following scheme function is just some mumbo-jumbo
%%% That you should add at the top of your program:
defineTransform =
#(define-scheme-function (parser location pattern)
(ly:music?)
(define-music-function (parser location pitchseq)
(ly:music?)
(let ((pitches (list->vector
(reverse!
(fold-some-music
(lambda (m)
(ly:pitch? (ly:music-property m 'pitch)))
(lambda (m l)
(cons (ly:music-property m 'pitch) l))
'()
pitchseq))))
(m (ly:music-deep-copy pattern)))
(for-some-music
(lambda (m)
(let ((p (ly:music-property m 'pitch)))
(and (ly:pitch? p)
(begin
(set! (ly:music-property m 'pitch)
(vector-ref pitches
(ly:pitch-steps p)))
#t))))
m)
m)))
%%% To illustrate, here follows the Bach Prelude in C major,
%%% Typeset using defineTransform:
% This is the unabridged version of the whole Prelude.
% If we were to implement it in the documentation, we
% might have to consider commenting about 80% of it. -vv
\include "deutsch.ly"
%%% This defines one measure of the prelude,
%%% using the five notes c' d' e' f' g' instead of the "real" notes:
makePreludeMeasure =
\defineTransform \transpose c c' \repeat unfold 2 {
<<
\context Staff = "up" {r8 e16 f g e f g }
\context Staff = "down" << {r16 d8.~d4 } \\ { c2 } >>
>>
}
%%% This is the last two measures - defined normally:
ending = <<
\context Staff = up { s1*2 }
\context Staff = up { r8 f,16 a, c f c a, \stemUp c \change Staff = down
a, f, a, f, d, f, d, \change Staff = up \stemNeutral
r8 g16 h d' f' d' h d' h g h d f e\prall d <e g c'>1^\fermata \bar "|."
}
\context Staff = down <<
\new Voice {
\stemUp \tieUp r16 c,8.~c,4~c,2 r16 h,,8.~h,,4~h,,2 c,1 \bar "|."
}
\new Voice {
\stemDown \tieDown c,,2~c,, c,,~c,, c,,1_\fermata
}
>>
>>
\header {
title = "Praeludium in C major"
composer = "J. S. Bach"
}
\score {
\transpose c c' \context PianoStaff <<
\new Staff = "up" { \clef "G" }
\new Staff = "down" { \clef "F"
\tempo 4 = 80
%%% The first measure should use notes c e g c' e' :
\makePreludeMeasure {c e g c' e' }
%%% Etc. :
\makePreludeMeasure {c d a d' f' }
%we get the idea now.
%comment the following block if the snippet is too long.
\makePreludeMeasure {h, d g d' f' }
\makePreludeMeasure {c e g c' e' }
\makePreludeMeasure {c e a e' a' }
\makePreludeMeasure {c d fis a d' }
\makePreludeMeasure {h, d g d' g' }
\makePreludeMeasure {h, c e g c' }
\makePreludeMeasure {a, c e g c' }
\makePreludeMeasure {d, a, d fis c' }
\makePreludeMeasure {g, h, d g h }
\makePreludeMeasure {g, b, e g cis' }
\makePreludeMeasure {f, a, d a d' }
\makePreludeMeasure {f, as, d f h }
\makePreludeMeasure {e, g, c g c' }
\makePreludeMeasure {e, f, a, c f }
\makePreludeMeasure {d, f, a, c f }
\makePreludeMeasure {g,, d, g, h, f }
\makePreludeMeasure {c, e, g, c e }
\makePreludeMeasure {c, g, b, c e }
\makePreludeMeasure {f,, f, a, c e }
\makePreludeMeasure {fis,, c, a, c es }
\makePreludeMeasure {as,, f, h, c d }
\makePreludeMeasure {g,, f, g, h, d }
\makePreludeMeasure {g,, e, g, c e }
\makePreludeMeasure {g,, d, g, c f }
\makePreludeMeasure {g,, d, g, h, f }
\makePreludeMeasure {g,, es, a, c fis }
\makePreludeMeasure {g,, e, g, c g }
\makePreludeMeasure {g,, d, g, c f }
\makePreludeMeasure {g,, d, g, h, f }
\makePreludeMeasure {c,, c, g, b, e }
%%% Finally insert the ending:
\ending
% here ends the block to comment
}
>>
\layout {}
\midi {}
}
--
David Kastrup
_______________________________________________
lilypond-user mailing list
lilypond-user@gnu.org
https://lists.gnu.org/mailman/listinfo/lilypond-user
