Re: Scheme: change duration of NoteEvent

[Lukas-Fabian Moser]

Hi Pavel,

Am 09.08.20 um 12:30 schrieb Павел:

> I want
>       to write simple function that will be change duration of note. But
>       I stuck on the first step: I can't "extract" (or "see") the
>       duration property:
>       
>       
>       \version "2.20.0"
>       
>       mynote = c'
>       
>       \displayMusic \mynote
>       
>       #(display-scheme-music
>       
>           (ly:music-property mynote 'duration))
>       
>

Try setting mynote = c'8 from the start.

LilyPond interprets your mynote as a naked pitch (and you obvioulsy can't extract a duration from a pitch). This can be seen by doing #(display-scheme-music mynote) which yields (ly:make-pitch 0 0), or simply by #(display mynote) which yields #<Pitch c' >.

It seems using \displayMusic hides this fact by first upgrading #mynote to a full-fledged NoteEvent; these implicit conversions happen all the time in LilyPond.

    Best
    Lukas