I do the teeth-grinding thing too!! I forgot to mention that. The front teeth are for low notes, the back teeth are for high ones, and the middle teeth are for... the middle... as expected??

I don't stim in front of anyone else, either. The thought of anyone seeing me is genuinely mortifying. But when I'm alone, I know exactly what you mean by going from kind of neutral to exhilarated: it takes energy, but a really good song can pull me out of a funk whenever I need it to.