Jessica, I know what you mean. When I was in high school all my friends pretty much listened to rap and hip-hop. I know they liked other music too, bc if I was alone with them at their house or something they'd play different kinds of music, but at school when they'd talk about music it was always what was in style. I remember I brought in this mix cd and played it for my friend and she said, "This is a good song" without me even asking if she liked it, and it was a newer, unreleased Hanson song... hahaha.
Once I got to college, the music repetoire seemed to expand, thankfully, for most people. I'm not sure if this is true of most colleges, but this big radius of closeby dorms all had linked itunes, so you could listen to anyone's library of music... so there was tons of access to people's tastes and they were, to put it lightly, diverse. hahah. That was one good thing about living in a dorm.