Re: GDP: NR 1.1 Pitches vastly improved, more comments sought

[Mats Bengtsson]

Graham Percival wrote:
> On Mon, 21 Jan 2008 11:24:22 +0100
> Mats Bengtsson <address@hidden> wrote:
>
>   
> > Graham Percival wrote:
> >     
> > > Some sections have been completely rewritten (particularly Octave
> > > check).  Please read the new Pitches section and send comments.
> > >   
> > >       
> > - The text in "Octave corrections and checks" is contradictory.
> >     
>
> Whoops!  My initial impression of these commands was completely
> incorrect; after creating the example shown on the page, I
> realized my mistake and fixed them... but apparently not
> everywhere.
>
>   
> > As far as I can see, the true difference between the two
> > commands is that the
> >   octave correction is specified as a attribute to the note itself in 
> > the input, whereas
> >   the octave check is a separate "command" to be inserted between
> > notes in the input.
> >   Both have the same effect of correcting the octave (not the pitch, 
> > right?) if it's wrong.
> >     
>
> Not true; with = the d's octave is changed; with \octave the d's
> octave is not changed.
>   
No! The difference is that = modifies the pitch on the current note, whereas
the \octave changes the pitch first on the note after the command, i.e.
\octave d' d is the same as d='

> > - The transposing-pitches-with-minimum-accidentals-smart-transpose.ly 
> > LSR example,
> >   included in "Transpose" didn't work, since the internal
> > representation for
> >   alterations has changed between 2.10 and 2.11. I have just tried to 
> > submit a
> >   2.11 version to LSR, but since it doesn't compile in 2.10, I'm not 
> > sure it
> >   was accepted in the LSR database. I'll send it by email otherwise.
> >     
>
> Please send it to me.  (I've complained to Valentin about this,
> but if you already have the solution, great)
>   

Attached! (It's not the most beautiful solution,but it should work.)
>   
 /Mats

\version "2.11.33"
#(define  (naturalise-pitch p)
  (let* ((o (ly:pitch-octave p))
         (a (* 4 (ly:pitch-alteration p))) 
    ; alteration, a, in quarter tone steps, for historical reasons
         (n (ly:pitch-notename p)))

    (cond
     ((and (> a 1) (or (eq? n 6) (eq? n 2)))
      (set! a (- a 2))
      (set! n (+ n 1)))
     ((and (< a -1) (or (eq? n 0) (eq? n 3)))
      (set! a (+ a 2))
      (set! n (- n 1))))

    (cond
     ((> a 2) (set! a (- a 4)) (set! n (+ n 1)))
     ((< a -2) (set! a (+ a 4)) (set! n (- n 1))))

    (if (< n 0) (begin (set!  o (- o 1)) (set! n (+ n 7))))
    (if (> n 6) (begin (set!  o (+ o 1)) (set! n (- n 7))))

    (ly:make-pitch o n (/ a 4))))

#(define (naturalise music)
  (let* ((es (ly:music-property music 'elements))
         (e (ly:music-property music 'element))
         (p (ly:music-property music 'pitch)))

    (if (pair? es)
        (ly:music-set-property!
         music 'elements
         (map (lambda (x) (naturalise x)) es)))

    (if (ly:music? e)
        (ly:music-set-property!
         music 'element
         (naturalise e)))

    (if (ly:pitch? p)
        (begin
          (set! p (naturalise-pitch p))
          (ly:music-set-property! music 'pitch p)))

    music))

music =  \relative c' { c4 d  e f g a b  c }

naturaliseMusic =
#(define-music-function (parser location m)
                                        (ly:music?)
                        (naturalise m))

\score {
   \new Staff {
     \transpose c ais \music
     \naturaliseMusic \transpose c ais \music 
    \break
    \transpose c deses \music
    \naturaliseMusic \transpose c deses \music
  }
  \layout { ragged-right = ##t}
}