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1.3.3 Music properties
Let’s look at an example:
someNote = c' \displayMusic \someNote ===> (make-music 'NoteEvent 'duration (ly:make-duration 2 0 1/1) 'pitch (ly:make-pitch 0 0 0))
The NoteEvent object is the representation of someNote.
Straightforward. How about putting c’ in a chord?
someNote = <c'>
\displayMusic \someNote
===>
(make-music
'EventChord
'elements
(list (make-music
'NoteEvent
'duration
(ly:make-duration 2 0 1/1)
'pitch
(ly:make-pitch 0 0 0))))
Now the NoteEvent object is the first object of the
'elements property of someNote.
The display-scheme-music function is the function used by
\displayMusic to display the Scheme representation of a music
expression.
#(display-scheme-music (first (ly:music-property someNote 'elements))) ===> (make-music 'NoteEvent 'duration (ly:make-duration 2 0 1/1) 'pitch (ly:make-pitch 0 0 0))
Then the note pitch is accessed through the 'pitch property
of the NoteEvent object.
#(display-scheme-music
(ly:music-property (first (ly:music-property someNote 'elements))
'pitch))
===>
(ly:make-pitch 0 0 0)
The note pitch can be changed by setting this 'pitch property.
#(set! (ly:music-property (first (ly:music-property someNote 'elements))
'pitch)
(ly:make-pitch 0 1 0)) ;; set the pitch to d'.
\displayLilyMusic \someNote
===>
d'4