I don't understand your goal, too.
But using (or abusing) some functions from
http://lists.gnu.org/archive/html/lilypond-user/2009-01/msg00685.htmland
http://lsr.dsi.unimi.it/LSR/Item?id=761
you could work with:
\version "2.14.2"
%
http://lists.gnu.org/archive/html/lilypond-user/2009-01/msg00685.html
#(define (has-duration? music)
(ly:duration? (ly:music-property music 'duration)))
#(define (not-has-duration? music)
(not (has-duration? music)))
keepsOnlyFirstNote = #(define-music-function (parser location music) (ly:music?)
(music-map
(lambda (evt)
(if (eq? 'EventChord (ly:music-property evt 'name))
(let ((elts (ly:music-property evt 'elements)))
(if (has-duration? (car elts))
(ly:music-set-property! evt 'elements (cons
(car elts)
(filter not-has-duration? (cdr elts)))))))
evt)
music))
deleteFirstNote = #(define-music-function (parser location music) (ly:music?)
(music-map
(lambda (evt)
(if (eq? 'EventChord (ly:music-property evt 'name))
(let ((elts (ly:music-property evt 'elements)))
(if (has-duration? (car elts))
(ly:music-set-property! evt 'elements (cdr elts)))))
evt)
music)
)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
http://lsr.dsi.unimi.it/LSR/Item?id=761%%%%%%%%%%%%%%%%%%%%% addNote
#(define-macro (add! lst elt)
"Add element `elt to the list `lst."
`(set! ,lst (append ,lst (list ,elt))))
#(define (join-list notes notes-to-add)
(let ((dur (ly:music-property (car notes) 'duration)))
(append
(filter
(lambda (elt) (and
(eq? 'NoteEvent (ly:music-property elt 'name)) ; keeps only notes
(ly:music-set-property! elt 'duration dur))); one duration for all notes
notes-to-add)
notes)))
addNote = #(define-music-function (parser location music notes)
(ly:music? ly:music?)
"Adds to the first chord found in `music, all the notes contained in the first
chord found in `notes, and then continues successively with the next chords."
(let ((chords-list '())
(relative-notes #{\relative { $notes } #}) ; the 2 music-parameters will
(relative-music #{\relative { $music } #})) ; be seen in \relative mode
(let loop ((evt relative-notes)) ; fills chords-list with chords 'elements
(let ((elt (ly:music-property evt 'element))
(elts (ly:music-property evt 'elements)))
(if (ly:music? elt) (loop elt))
(if (pair? elts)(cond
((eq? 'EventChord (ly:music-property evt 'name)) ; if evt is a
(if (memq (ly:music-property (car elts) 'name) ; note,
(list 'NoteEvent)) ; (but not a rest)
(add! chords-list elts))) ; add evt 'elements
(else (for-each loop elts))))))
(let loop ((evt relative-music)) ; joins notes of `music and `notes.
(let ((elt (ly:music-property evt 'element))
(elts (ly:music-property evt 'elements)))
(if (ly:music? elt) (ly:music-set-property! evt 'element (loop elt)))
(if (pair? elts)
(cond
((eq? 'EventChord (ly:music-property evt 'name))(and
(eq? 'NoteEvent (ly:music-property (car elts) 'name))
(pair? chords-list)
(ly:music-set-property! evt 'elements
(join-list elts (car chords-list)))
(set! chords-list (cdr chords-list)))) ; next chords-list elt ...
(else (ly:music-set-property! evt 'elements (map loop elts)))))
evt))))
makeMajorChord = #(define-music-function (parser location music) (ly:music?)
#{
\addNote \transpose c g \relative { $music }
\addNote \transpose c e
\relative { $music }
$music
#})
%----- test
normalChords = \chordmode {
r \deleteFirstNote { c2/b } s g:m r4 f8:sus2 d8:m7
r4 g:m r4 f8 d8:m7 d1:11 ees:m13
}
changedChords = \chordmode { \makeMajorChord \keepsOnlyFirstNote \normalChords }
\score {
\chords { \changedChords }
\layout {
\context {
\ChordNames
noChordSymbol = ##f
chordChanges = ##t
}
}
}
\score {
\chords { \normalChords }
\midi {}
}