RE: Generate pitches between pitches

[lilypond]

 

 

From: lilypond-user <lilypond-user-bounces+lilypond=address@hidden> On Behalf Of Paolo Prete
Sent: Friday, November 29, 2019 12:27 AM
To: Lilypond-User Mailing List <address@hidden>
Subject: Generate pitches between pitches

 

Hello,

 

given two pitches, for example: c' and c'',   is there a way to automatically generate all the pitches between them? In three different ways:

 

1) all the "white keys" between them:   d' e' f' g' a' b'

2) all the "black keys" between them:   des' ees' ges' aes' bes'

3) all the pitches:  des' d' ees' e' f' ges' g' aes' a' bes' b'

 

This feature would be very useful for simulating (piano) glissandos with MIDI.

 

thanks.

[>]

 

Like this?

 

\version "2.19.83"

 

glisando =

#(define-music-function

     (parser location arg1 arg2)

     (ly:music? ly:music? )

   (letrec

         ((first-note-fn (lambda (lst)

             (cond

                ((ly:music? lst) lst)

                ((null? lst) '())

               ((not (pair? lst)) '())

                (else (car lst)))))

         (last-note-fn (lambda (lst)

             (cond

               ((ly:music? lst) lst)

               ((null? lst) '())

               ((not (pair? lst)) '())

               ((null? (cdr lst)) (car lst))

               (else (last-note-fn (cdr lst)))))))

         (let*

         ((lst1 (ly:music-property arg1 'elements))

         (lst2 (ly:music-property arg2 'elements))

         (pp-pitch '((0 . (0 . 0))

                     (1 . (1 . -1/2 ))

                     (2 . (1 . 0))

                     (3 . (2 . -1/2 ))

                     (4 . (2 . 0))

                     (5 . (3 . 0))

                     (6 . (4 . -1/2 ))

                     (7 . (4 . 0))

                     (8 . (5 . -1/2 ))

                     (9 . (5 . 0))

                     (10 . (6 . -1/2 ))

                     (11 . (6 . 0))))

         (make-pitch (lambda (p)

                        (let* ((note (assoc-get (modulo p 12) pp-pitch))

                               (octave (quotient p 12)))

                              (ly:make-pitch octave (car note) (cdr note)))))

         (first-note (last-note-fn lst1))

         (last-note (first-note-fn lst2))

         (first-pitch (ly:music-property first-note 'pitch))

         (last-pitch (ly:music-property last-note 'pitch))

         (first-duration (ly:duration-log (ly:music-property first-note 'duration)))

         (first-type (ly:music-property first-note 'name))

         (last-type (ly:music-property last-note 'name)))

     (cond ((null? first-note) (throw 'glisando-err

                       "arg1 must be a music _expression_ with notes"))

       ((null? last-note) (throw 'glisando-err

                       "arg2 must be a music _expression_ with notes"))

       ((not (equal? first-type 'NoteEvent))(throw 'glisando-err

                       "arg1 must end with a note"))

       ((not (equal? last-type 'NoteEvent))(throw 'glisando-err

                       "arg2 must begin with a note"))

        (else

          (let* ((ps-first (ly:pitch-semitones first-pitch))

                  (ps-last ( - (ly:pitch-semitones last-pitch) 1))

                  (dir (if (> ps-first ps-last) 1+ 1- ))

                  (glis '()))

         (do ((p ps-last (dir p)))((equal? p ps-first))

            (set! glis (cons

            (make-music

            'NoteEvent

            'pitch

            (make-pitch p)

            'duration

            (ly:make-duration first-duration)

            ) glis)))

 

          (make-music 'SequentialMusic 'elements (append (list arg1) glis  (list arg2) ))))

   ))))

 

\glisando { e'2 d' c'32 } { c''4 b' a'}