Re: Nashville notation as chord symbols

[Thomas Morley]

2015-06-19 6:48 GMT+02:00 David Kastrup <address@hidden>:
> Thomas Morley <address@hidden> writes:
>
>> 2015-06-18 23:37 GMT+02:00 David Kastrup <address@hidden>:
>>> Thomas Morley <address@hidden> writes:
>>>>
>>>> \version "2.18.2"
>>>>
>>>> #(define nashville-chord-engraver
>>>>    (let ((root (ly:make-pitch 0 0 0)))
>>>
>>> That should rather be
>>>
>>> #(define (nashville-chord-engraver context)
>>>    (let ((root (ly:make-pitch 0 0 0)))
>>> [...]
>>>
>>
>> Thanks.
>>
>> Not sure what exactly you mean with the following.
>> Is it an additional comment to the above or a second concern?
>>
>>> In your proposal, all engraver instances share the same "root", a recipe
>>> for trouble.
>
> It is an additional comment on the above.  If you have one transposed
> voice, for example, having all engravers working with the same "root" is
> not going to be a good idea.  Or when having a \markup { \score ... }
> inside for some purpose, there will still only be one root for both the
> enclosing score and the score inside the markup.
>
> --
> David Kastrup

Hi David,

if I understand your hints correctly, then some use-cases will break
or at least return wrong/weird output.
Though, I wasn't able to find any.
May I ask you, if you've the time to find and supply an example,
triggering the problem?

Here, what I've tried so far (the mainly unchanged engraver is included):

\version "2.18.2"

#(define (nashville-chord-engraver context)
   (let ((root (ly:make-pitch 0 0 0)))

     (define (note-name->international-markup pitch lowercase?)
       (let* ((diff (ly:pitch-diff pitch root))
              (name (ly:pitch-notename diff))
              (alt (ly:pitch-alteration diff))
              (hspace (vector-ref #(0.15 0.15 0.05 0.05 0.15) (+ (* alt 2) 2)))
              (raise (vector-ref #(0.6 0.6 0.65 0.8 0.7) (+ (* alt 2) 2))))

         (make-line-markup
           (list
             (if (= alt 0)
                 ;; If it's natural and not b, do nothing
                 (make-line-markup (list empty-markup))
                 ;; Else add alteration
                 (make-line-markup
                   (list
                     (make-smaller-markup
                       (make-raise-markup raise
                          (make-musicglyph-markup
                            (assoc-get
                              alt
                              standard-alteration-glyph-name-alist ""))))
                     (make-hspace-markup hspace))))
             (make-simple-markup
               (vector-ref #("1" "2" "3" "4" "5" "6" "7") name))))))

     (make-engraver
      (listeners
       ((key-change-event engraver event)
         (set! root (ly:event-property event 'tonic))
         (set! (ly:context-property context 'chordRootNamer)
               note-name->international-markup))))))

%%%%%%%%%%%%%%%%%%%%
%% EXAMPLE
%%%%%%%%%%%%%%%%%%%%

\paper { indent = 0 }

\layout {
  \context { \Score \omit BarNumber }
  \context { \ChordNames \consists #nashville-chord-engraver }
}

mI =
\chordmode {
    \key c \major
    c1 d:m
    \break
    \key d \major
    c_\markup {
            \score {
                    <<
                    \new ChordNames
                      \transpose d bes, \chordmode { \key d \major c }
                    \new Staff
                      \transpose d bes, \chordmode { \key d \major c }
                    >>
            }
    }
    d
}

mII =
\chordmode {
    \key c \major
    c1
    \key d \major
    d:m c d
}

\score {
  \new StaffGroup
    <<
      \new ChordNames \mI
      \new Staff \mI

      \new ChordNames \transpose c d \mII
      \new Staff \transpose c d \mII
    >>

}

Thanks,
  Harm