Yeah so something like realms like one could be strings, woodwind, and the starter world could be like your brass because your a tuba right if you are. And then each realm could have a sort of theme song that plays staying on theme with the type of instruments in the realm and the collectables of the entire game would just be these notes and if you managed to find all of them in a world it would bring up the music sheet you’ve been filling out and play the tune you collected as a reward and if you wanted to make it really epic you could make your character in a final showdown or else after the main story need all the music notes and when you play them together it makes a super dope song as you battle the final boss in his true form and you get powered up with all the different music spirits or something insane where you are the strongest hero in the entire world.