Fretless - The Wrath of Riffson on Steam
store.steampowered.com
In this turned-based RPG, wield powerful legendary instruments, gather mighty riff attacks and save the land from Rick Riffson's devilish goons and musical hybrid monsters!

Sure hope this goes here. Did not really see anything indicating heavy roleplaying, but not sure how friendly JRPGs are to genre crossing, and I think this crosses with rhythm games and deck building.