About the scale, do you have problems with midi note? I believe this would be the most compatible with other functions.
Well, normally I use midi note numbers or a transposed version thereof (especially : midi note minus a multiple of 12), but in this case, I have only implemented «white keys», and then, I wonder what you expect the interface to be, to implement the «black keys», and whether those numbers should be displayed as diÚse or bémol.
I think I will use the vertical space as something as equally divided as possible into midi notes, and then display all of them as either
unaltered or diÚse. Later, the latter part can be modified to show notes in any other chosen scale, maybe...And I want an option to hide the clef de Sol (thinking of it in the context of using it as a [#many] component, hypothesising a future in which [#many] supports an abstraction name as its $1).
don't forget that chromatic pitches is just a small fraction of what's
available. then there's quarter-, eight-, sixteenth-, etc. tones (just to
say some for which there exist already notation standards), "natural"
tunings (harmonic series), other tunings, cent notation...
as I see it, no notation object is complete without being possible to
incorporate these as well (I didn't download your object yet, so didn't
see how you do it).