Drummer Rob Bourdon was born on January 20, 1979, in Calabasas, CA, making him the youngest member of rap-metal powerhouse Linkin Park. He began playing drums in elementary school after attending an Aerosmith concert with his mother, and played in the band Relative Degree with future Linkin Park bandmate Brad Delson while in high school in Agoura Hills, CA (the same school attended by members of modern rockers Hoobastank). When Relative Degree fell apart, Bourdon and Delson teamed up with schoolmate Mike Shinoda in the band Xero. The group kept running even after high school was over, evolving over time into a sextet and eventually becoming the multi-platinum-selling act Linkin Park. The band debuted in 2000 with the album Hybrid Theory, going on to become one of the most popular mainstream rock acts in the early 2000s.