A bard/artist game that really makes use of the creative potential of music/painting. A great example of a "tech demo" of what I'd like is the magic system in Tchia. You got a ukulele that you can play super freely (possibly the most realistic thing if you don't play it irl), but depending on what notes you play, you unleash different spells (kinda like in the old Zelda games with the ocarina).

I would absolutely love if the creative spell freedom of Magicka (or Fictorum) was combined with the freeform instrument play of Tchia.