The Drummer Hat is a obtainable hat in the PFS store. The hat is a long red hat with gold linings.
Banging those tunes from your musical box... I mean, cylindrical drum. Well, that's the main purpose of this hat, isn't it?
Well, apart from the fact that you are most likely going to find one in a marching band, I hear these are pretty rare. Those gold linings definitely have a role in the worth of this elusive hat.