Might as well toss this here, a very simplified version of the horrifically complex key input processing for the project which will never end. It lets you get lists of symbols.
Edit: [list store] is probably better than [pird] for most peoples needs but [pird] will also be fine for most needs.
Unfortunately never finished the graphical part, but hopefully will do it one day.
I have one of those as well, never could quite get polyrhythms to work with a reasonable ppq, screen would always start lagging. Always meant to try it with data structures to see if that would solve it but never got around to it.