Re: different pitches with the same rhythm

[Stefan Thomas]

Dear Rune,
thanks very much for Your efforts, trying to explain me the function
of the program.
I tried it with  a short example, but it did'nt work.
I wanted an outpout like:
\relative c {c4 c8 d e4 d d d8 e f4 e } and so on.

Can You help me finding the mistake in the below quoted  file?
defineTransform =
#(define-music-function (parser location name pattern)
   (symbol? ly:music?)
   (letrec ((trans-rec
            (lambda (pitches)
             (lambda (music)
              (let* ((es (ly:music-property music 'elements))
                     (e (ly:music-property music 'element))
                     (p (ly:music-property music 'pitch)))
        
               (if (pair? es)
                (ly:music-set-property!
                 music 'elements
                 (map (trans-rec pitches) es)))
        
               (if (ly:music? e)
                (ly:music-set-property!
                 music 'element
                 ((trans-rec pitches) e)))
        
               (if (ly:pitch? p)
                (let* ((o (ly:pitch-octave p))
                       (n (ly:pitch-notename p))
                       (i (+ (* 7 o) n))
                       (pes (ly:music-property (list-ref pitches i) 'elements))
                       (pnew (ly:music-property (car pes) 'pitch))
                     )
                 (ly:music-set-property! music 'pitch pnew)
               ))
               music)))))
    (primitive-eval
     `(define ,name
       (define-music-function (parserb locationb pitchseq)
        (ly:music?)
        (let* ((pitches (ly:music-property pitchseq 'elements))
              (n       (ly:music-property pitchseq 'name)))
        (if (not (equal? n 'SequentialMusic))
         (ly:warning "2nd arg of transform must be SequentialMusic, got ~a"
n)
         ((,trans-rec pitches) (ly:music-deep-copy ,pattern)))))))
    (make-music 'SequentialMusic 'void #t)))

\define transform #'myTransformation { c'4 c'8 d'8 e'4 d'4 }

\score { 
 \myTransformation { c' d' e' } \myTransformation { d' e' f' }
 }
 
Rune Zedeler schrieb am 10.12.2007:

----------<snip>-----------
defineTransform =
#(define-music-function (parser location name pattern)
   (symbol? ly:music?)
   (letrec ((trans-rec
            (lambda (pitches)
             (lambda (music)
              (let* ((es (ly:music-property music 'elements))
                     (e (ly:music-property music 'element))
                     (p (ly:music-property music 'pitch)))
        
               (if (pair? es)
                (ly:music-set-property!
                 music 'elements
                 (map (trans-rec pitches) es)))
        
               (if (ly:music? e)
                (ly:music-set-property!
                 music 'element
                 ((trans-rec pitches) e)))
        
               (if (ly:pitch? p)
                (let* ((o (ly:pitch-octave p))
                       (n (ly:pitch-notename p))
                       (i (+ (* 7 o) n))
                       (pes (ly:music-property (list-ref pitches i) 'elements))
                       (pnew (ly:music-property (car pes) 'pitch))
                     )
                 (ly:music-set-property! music 'pitch pnew)
               ))
               music)))))
    (primitive-eval
     `(define ,name
       (define-music-function (parserb locationb pitchseq)
        (ly:music?)
        (let* ((pitches (ly:music-property pitchseq 'elements))
              (n       (ly:music-property pitchseq 'name)))
        (if (not (equal? n 'SequentialMusic))
         (ly:warning "2nd arg of transform must be SequentialMusic, got ~a"
n)
         ((,trans-rec pitches) (ly:music-deep-copy ,pattern)))))))
    (make-music 'SequentialMusic 'void #t)))
----------<snip>-----------
Stefan Thomas
Siebengebirgsallee 9
50939 Koeln
Tel.Fax:0049(0)221/412529
mail: address@hidden