43 lines
1.3 KiB
LilyPond
Executable File
43 lines
1.3 KiB
LilyPond
Executable File
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#(define (naturalize-pitch p)
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(let ((o (ly:pitch-octave p))
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(a (* 4 (ly:pitch-alteration p)))
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;; alteration, a, in quarter tone steps,
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;; for historical reasons
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(n (ly:pitch-notename p)))
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(cond
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((and (> a 1) (or (eq? n 6) (eq? n 2)))
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(set! a (- a 2))
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(set! n (+ n 1)))
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((and (< a -1) (or (eq? n 0) (eq? n 3)))
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(set! a (+ a 2))
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(set! n (- n 1))))
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(cond
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((> a 2) (set! a (- a 4)) (set! n (+ n 1)))
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((< a -2) (set! a (+ a 4)) (set! n (- n 1))))
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(if (< n 0) (begin (set! o (- o 1)) (set! n (+ n 7))))
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(if (> n 6) (begin (set! o (+ o 1)) (set! n (- n 7))))
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(ly:make-pitch o n (/ a 4))))
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#(define (naturalize music)
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(let ((es (ly:music-property music 'elements))
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(e (ly:music-property music 'element))
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(p (ly:music-property music 'pitch)))
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(if (pair? es)
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(ly:music-set-property!
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music 'elements
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(map (lambda (x) (naturalize x)) es)))
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(if (ly:music? e)
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(ly:music-set-property!
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music 'element
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(naturalize e)))
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(if (ly:pitch? p)
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(begin
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(set! p (naturalize-pitch p))
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(ly:music-set-property! music 'pitch p)))
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music))
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naturalizeMusic =
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#(define-music-function (parser location m)
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(ly:music?)
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(naturalize m)) |