In around 1996 there was a copy of Music for the Jilted Generation by The Prodigy that was secretly passed around school. Someone got it from their older brother and to our tender ears it felt new and dangerous and rebellious.
Before this all the music I heard came from my dad's record collection, so the self titled black sabbath album was heavy and terrifying and awe inspiring, but still reasonably conventional. I'd never heard real electronic music.