Re: creating chords like F/A(D/F#) with \chordmode { }

[Thomas Morley]

2016-03-12 18:30 GMT+01:00 Klaus Blum <address@hidden>:
> It looks like the goal is to create alternative chords in a different key,
> e.g for a guitar with a capo on the 3rd fret.
>
> A function to put chordnames into parentheses (better than \parenthesize)
> can be found here:
> http://www.lilypondforum.de/index.php?action=profile;area=showposts;u=54
>
> Here is what I would try:
>
> % -----------------------------------------------------------------------
> \version "2.19.25"
>
> #(define (parenthesis-ignatzek-chord-names in-pitches bass inversion
> context)
>    (markup #:line ( "(" (ignatzek-chord-names in-pitches bass inversion
> context) ")" )))
>
> klamm = #(define-music-function (parser location griffe) (ly:music?)
>            #{
>              \set chordNameFunction = #parenthesis-ignatzek-chord-names
>              $griffe
>              \set chordNameFunction = #ignatzek-chord-names
>            #})
>
>
> \score {
>   <<
>     \new ChordNames \chordmode {
>       c2 c/e f g
>     }
>     \new ChordNames \transpose c a \chordmode {
>       \klamm { c2 c/e f g }
>     }
>     \new Staff \relative c'' {
>       c2 c a4 c b2
>     }
>   >>
> }
>
> \score {
>   <<
>     \new ChordNames \chordmode {
>       c16 \klamm a4.. c16/e \klamm a4../cis  f16 \klamm d4.. g16 \klamm e4..
>     }
>     \new Staff \relative c'' {
>       c2 c a4 c b2
>     }
>   >>
> }
> % -----------------------------------------------------------------------
>
> Cheers,
> Klaus



Here my own approach.

The function always needs two music-expressions, supposed to be
event-chords, as arguments.
This may be an advantage or disadvantage depending on the use-case.
Furthermore there are some TODOs. Thoroughly testing is recommended ...


\version "2.19.36"

#(define (pitches-bass-inversion-context-list music context)
"Creates a list containing relevant pitches, bass, inversion and context to
serve as argument for `ignatzek-chord-names', derived from @var{music}
"
  (let* (;; work on a copy of `music', warranting not to change it
         (m-add (ly:music-deep-copy music))
         (ev-notes-orig (event-chord-notes m-add))
         ;; if chord is an inversion some pitches are below root, in this case
         ;; 'octavation-property is set.
         ;; reset pitch of them
         ;; TODO this is an ugly hack, find better method
         (ev-notes
           (map
             (lambda (m)
               (if (and (not (null? (ly:music-property m 'octavation)))
                        (= (ly:music-property m 'octavation) -1))
                   (begin
                     (ly:music-set-property! m 'pitch
                       (ly:pitch-transpose
                         (ly:music-property m 'pitch)
                         (ly:make-pitch 1 0 0)))
                      m)
                   m))
             ev-notes-orig))
         ;; sort the ptches ascending as expected by `ignatzek-chord-names'
         (ev-pitches
           (sort
             (map (lambda (m) (ly:music-property m 'pitch)) ev-notes)
             ly:pitch<?))
         ;; get bass
         (bass-note
             (filter
               (lambda (m)
                 (not (null? (ly:music-property m 'bass))))
               ev-notes))
         (bass-pitch
           (if (not (null? bass-note))
               (ly:music-property (car bass-note) 'pitch)
               '()))
         ;; get inversion
         (inversion-note
           (filter
             (lambda (m)
               (not (null? (ly:music-property m 'inversion))))
             ev-notes))
         (inversion-pitch
           (if (not (null? inversion-note))
               (ly:music-property (car inversion-note) 'pitch)
               '()))
         ;; TODO why is this needed?
         (in-pitches
           (if (null? inversion-pitch)
               (delq bass-pitch ev-pitches)
               ev-pitches)))

    (list in-pitches bass-pitch inversion-pitch context)))

altChords =
#(define-music-function (m1 m2)(ly:music? ly:music?)
"Return the default ChordName of @var{m1}, with an added parenthesized ChordName
derived from @var{m2}"
#{
   \applyOutput ChordNames.ChordName
     #(lambda (g ctx p)
        (let ((main-text (ly:grob-property g 'text))
              (alt-text
                (apply
                  ignatzek-chord-names
                  (pitches-bass-inversion-context-list m2 ctx))))
         (ly:grob-set-property! g 'text
           #{
             \markup
               { $main-text \hspace #0.4 \fontsize #-3 \parenthesize $alt-text }
           #})))
   $m1
#})

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

m =
\chordmode {
  \altChords c1 e:m7/e
  \altChords c1 e:m9/dis
  \altChords c1 e:m11/d
  \break
  \altChords c1 e:m7/des
  \altChords c1 e:m7/c
  \altChords bes2 g
  \altChords f/a d/fis
}

<<
  \new ChordNames \m
  \new Staff \m
>>

Cheers,
  Harm