Brilliant idea, I just suck at this game :D The art is beautiful and I love the twist that you have to make the sounds of the instruments, made me smile :)
Just one tiny thing: While I think the "booing" is immersive and in universe if you miss a lot (what happend to me) the sound is overlapping and monotone. Maby use a shorter sound from booing of a single person and not from a crowed and try to pitch variant it to make it sound it comes from different persones. I don't know if this works but in my head it sounds cool :D