Re: custom replace/map of one set of pitches to another

[Lukas-Fabian Moser]

Hi Valentin,

Am 01.09.23 um 00:41 schrieb Valentin Petzel:
> I don’t think this is a particularly good idea. Lilypond conceptually first
> creates data for the sementic meaning of the music (or the actual content) and
> have engravers turn this into graphical content.
>
> Mapping pitches to other pitches is not a layout option, but a musical
> transformation and should thus be done on the music level, not the layout
> level. Using an engraver will mean it is hard to combine this with other
> musical transformations, and it will also cause order issues as soon as you
> have an engraver that depends on the pitch property.

I agree about the possible problems, and to be honest, I wasn't aware 
that a music function solution like yours can deal with \transpose and 
\relative gracefully (since the assignment of actual pitches is complete 
when the music function is applied on the outside).

What I don't necessarily agree with is the philosophical notion of 
engravers being tied to the layout level (which is admittedly suggested 
by their name): As long as I work with listeners (as opposed to 
acknowledgers), I see no problem in using them for "semantic" 
transformations that need the music sorted by timestep (which 
nevertheless is not the case in the current situation).

Lukas