1 %% Do not edit this file; it is auto-generated from input/new
2 %% This file is in the public domain.
5 doctitle = "Transposing music with minimum accidentals"
7 texidoc = "There is a way to enforce enharmonic modifications for
8 notes in order to have the minimum number of accidentals. In that
9 case, ``Double accidentals should be removed, as well as E-sharp
10 (-> F), bC (-> B), bF (-> E), B-sharp (-> C).'', as proposed by a
11 request for a new feature. In this manner, the most natural
12 enharmonic notes are chosen in this example. "
15 #(define (naturalise-pitch p)
16 (let* ((o (ly:pitch-octave p))
17 (a (* 4 (ly:pitch-alteration p)))
18 ; alteration, a, in quarter tone steps, for historical reasons
19 (n (ly:pitch-notename p)))
22 ((and (> a 1) (or (eq? n 6) (eq? n 2)))
25 ((and (< a -1) (or (eq? n 0) (eq? n 3)))
30 ((> a 2) (set! a (- a 4)) (set! n (+ n 1)))
31 ((< a -2) (set! a (+ a 4)) (set! n (- n 1))))
33 (if (< n 0) (begin (set! o (- o 1)) (set! n (+ n 7))))
34 (if (> n 6) (begin (set! o (+ o 1)) (set! n (- n 7))))
36 (ly:make-pitch o n (/ a 4))))
38 #(define (naturalise music)
39 (let* ((es (ly:music-property music 'elements))
40 (e (ly:music-property music 'element))
41 (p (ly:music-property music 'pitch)))
44 (ly:music-set-property!
46 (map (lambda (x) (naturalise x)) es)))
49 (ly:music-set-property!
55 (set! p (naturalise-pitch p))
56 (ly:music-set-property! music 'pitch p)))
60 music = \relative c' { c4 d e f g a b c }
63 #(define-music-function (parser location m)
69 \transpose c ais \music
70 \naturaliseMusic \transpose c ais \music
72 \transpose c deses \music
73 \naturaliseMusic \transpose c deses \music
75 \layout { ragged-right = ##t}