Re: how do I change enharmonic spellings produced by the /transpose function?

[David Kastrup]

robert edge <address@hidden> writes:

> I write music that is not strictly tonal, and years ago I adopted the
> convention of always using the same enharmonic spellings.  So my
> chromatic scale goes: c cis d ees e f fis g aes a bes b.  I never
> write something like an A sharp or a G flat.
>
> Of course Lilypond doesn't know about my silly ideas and \transpose
> gives me all sorts of g sharps and d sharps in my tenor sax charts,
> for instance.
>
> My current workflow is transposing the chart using \transpose, using
> the \displayLilyMusic function, pasting the output back in to the
> source file and then making the changes using search and replace in
> EMACS.
>
> I'd like to automate this process, I've got a lot of charts.  
>
> Anyone have any ideas on how to do this, or where I can find some code
> that does something similar I might be able to adapt?

How about the following:

myScale =
#(event-chord-pitches #{ <c cis d ees e f fis g aes a bes b> #})

chromaScale =
#(define-music-function (parser location music) (ly:music?)
   (for-some-music
     (lambda (m)
       (and (ly:pitch? (ly:music-property m 'pitch))
            (let* ((s (ly:pitch-semitones (ly:music-property m 'pitch)))
                   (oct (floor (/ s 12)))
                   (step (modulo s 12))
                   (p (list-ref myScale step)))
              (set! (ly:music-property m 'pitch)
                    (ly:make-pitch oct
                                   (ly:pitch-notename p)
                                   (ly:pitch-alteration p))))
             #t))
     music)
  music)

\chromaScale \relative c' { c des es fes ceses }

-- 
David Kastrup