What piano genre do each of these song selections pertain to?

I am organizing all of my sheet music into 4 different binders. I can't decide which each binder should be called though, as in what genre each peice of music in it pertains to. In one binder, i have pop songs you'd hear on the radio. In the second, i have classic piano songs like bohemian rhapsody, faithfully, ect, and popular songs that you wouldn't hear on the radio, kind of like death cab for cutie, journey, and so on. In the third I have piano solos like brian crain and george winston. In the forth, i have sad/beautiful, slow, and heartfelt songs and ballads. What genre pertains to each of these binders? Thanks!:)