coloratio, black mensural notation

[Benkő Pál]

hi list,

the attached patch adds noteheads needed for black mensural notation (BMN)
and coloratio in white mensural notation (WMN).

note that it's just the noteheads: in both BMN and coloratio sections
in WMN a fourth note looks like a flagged half note.
I could reach this look by the following functions:

#(define (nota-colorata music)
  (let (
    (es (ly:music-property music 'elements))
    (name (ly:music-property music 'name))
  )
   (if (equal? name 'EventChord)
    (let* ((note (first es))
           (dur (ly:music-property note 'duration))
           (dl (ly:duration-log dur))
         )
     (if (> dl 1)
      (set! music (shift-duration-log
                   (ly:music-compress music (ly:make-moment 2 1))
                   1 0)))))
   music))

notaColorata =
#(define-music-function (parser location mus) (ly:music?)
  (music-map nota-colorata mus))

I hope there is a better solution.

the next step is using all this;
I've tried adding a new note head style - I believe this
is right, considering colored - uncolored changes in
WMN, but I may well be wrong.

I also have support for these in ligatures (notes can
be colored/uncolored independently - even the two notes
of a flexa can have different color), but I'd like to
sort out the above issues first.

thanks,
Pal

black.patch
Description: Binary data