this sounds really neat! i love making music and i also love haskell (although i am only a hobbyist at either one).

It's nice to see another person in this intersection of interests, I wouldn't have guessed! I'm not a career programmer by any means, so Haskell is a hobby for me too.

have you picked a web framework yet? i've seen a few for haskell but haven't tried any.

No I haven't and this has been a point of procrastination for me. I think I should pick one, make something that outputs on the page the same [e♭,F,g,b♭,e♭,c,e♭,b,E,d] kinda string as my current program does, and refreshes it every time you click a button. Pimintel's app isn't much more fancy than that in the big picture, after all.

A problem is that there are lots of choices, but the situation keeps developing so I can't what's good. Year old blog posts are outdated at this point afaik.