Right now you have to enter a table of frequencies which is a pain in the ass, and then it processes it offline which can take 30 sec or so.
You could also make an offline program where all notes/frequencies get processed and then written to a file. That would be the easiest programmable way IMHO, since wave files are not that hard to understand.
Btw: I imagine an interface like a "graph editor".... means we don't need to change every single value, only points with interpolated values between them (you said you're using an array). I don't know how you've done that awesome sound, but please experiment a bit, before making something usable. And interface with the ability to produce an alghorythmic value fill is very useful for additive synthesis - even for the programmer!