input/lsr/transposing-pitches-with-minimum-accidentals-smart-transpose.ly

   1 %% Do not edit this file; it is auto-generated from input/new
   2 %% This file is in the public domain.
   3 \version "2.12.0"
   4 \header {
   5 doctitlees = "Transportar música con el menor número de alteraciones"
   6 texidoces = "
   7 Este ejemplo utiliza código de Scheme para forzar las
   8 modificaciones enarmónicas de las notas, y así tener el menor
   9 número de alteraciones accidentales. En este caso se aplican las
  10 siguientes reglas:
  11
  12 @itemize
  13 @item
  14 Se quitan las dobles alteraciones
  15
  16 @item
  17 Si sostenido -> Do
  18
  19 @item
  20 Mi sistenido -> Fa
  21
  22 @item
  23 Do bemol -> Si
  24
  25 @item
  26 Fa bemol -> Mi
  27
  28 @end itemize
  29
  30 De esta forma se selecciona el mayor número de notas enarmónicas
  31 naturales.
  32
  33 "
  34
  35 doctitlede = "Noten mit minimaler Anzahl an Versetzungszeichen transponieren."
  36
  37 texidocde = "Dieses Beispiel benutzt Scheme-Code, um enharmonische
  38 Verwechslungen für Noten zu erzwingen, damit nur eine minimale Anzahl
  39 an Versetzungszeichen ausgegeben wird.  In diesem Fall gelten die
  40 folgenden Regeln:
  41
  42 @itemize
  43 @item
  44 Doppelte Versetzungszeichen sollen entfernt werden
  45
  46 @item
  47 His -> C
  48
  49 @item
  50 Eis -> F
  51
  52 @item
  53 Ces -> B
  54
  55 @item
  56 Fes -> E
  57
  58 @end itemize
  59
  60 Auf diese Art werden am meisten natürliche Tonhöhen als enharmonische
  61 Variante gewählt.
  62 "
  63
  64
  65   lsrtags = "pitches"
  66   texidoc = "This example uses some Scheme code to enforce enharmonic
  67 modifications for notes in order to have the minimum number of
  68 accidentals.  In this case, the following rules apply:
  69
  70 @itemize
  71 @item
  72 Double accidentals should be removed
  73
  74 @item
  75 B sharp -> C
  76
  77 @item
  78 E sharp -> F
  79
  80 @item
  81 C flat -> B
  82
  83 @item
  84 F flat -> E
  85
  86 @end itemize
  87
  88 In this manner, the most natural enharmonic notes are chosen.
  89 "
  90   doctitle = "Transposing music with minimum accidentals"
  91 } % begin verbatim
  92
  93
  94 #(define  (naturalize-pitch p)
  95   (let* ((o (ly:pitch-octave p))
  96          (a (* 4 (ly:pitch-alteration p)))
  97     ; alteration, a, in quarter tone steps, for historical reasons
  98          (n (ly:pitch-notename p)))
  99     (cond
 100      ((and (> a 1) (or (eq? n 6) (eq? n 2)))
 101       (set! a (- a 2))
 102       (set! n (+ n 1)))
 103      ((and (< a -1) (or (eq? n 0) (eq? n 3)))
 104       (set! a (+ a 2))
 105       (set! n (- n 1))))
 106     (cond
 107      ((> a 2) (set! a (- a 4)) (set! n (+ n 1)))
 108      ((< a -2) (set! a (+ a 4)) (set! n (- n 1))))
 109     (if (< n 0) (begin (set! o (- o 1)) (set! n (+ n 7))))
 110     (if (> n 6) (begin (set! o (+ o 1)) (set! n (- n 7))))
 111     (ly:make-pitch o n (/ a 4))))
 112
 113 #(define (naturalize music)
 114   (let* ((es (ly:music-property music 'elements))
 115          (e (ly:music-property music 'element))
 116          (p (ly:music-property music 'pitch)))
 117     (if (pair? es)
 118         (ly:music-set-property!
 119          music 'elements
 120          (map (lambda (x) (naturalize x)) es)))
 121     (if (ly:music? e)
 122         (ly:music-set-property!
 123          music 'element
 124          (naturalize e)))
 125     (if (ly:pitch? p)
 126         (begin
 127           (set! p (naturalize-pitch p))
 128           (ly:music-set-property! music 'pitch p)))
 129     music))
 130
 131 naturalizeMusic =
 132 #(define-music-function (parser location m)
 133                                         (ly:music?)
 134                         (naturalize m))
 135
 136 music = \relative c' { c4 d e g }
 137
 138 \score {
 139   \new Staff {
 140     \transpose c ais { \music }
 141     \naturalizeMusic \transpose c ais { \music }
 142     \transpose c deses { \music }
 143     \naturalizeMusic \transpose c deses { \music }
 144   }
 145   \layout { }
 146 }