Starting out around the age of nine, Bourdon joined his first band, a quartet called No Clue. They later changed their name to Physical Evidence. Rob took drum lessons for a year, but became tired of reading sheet music because he enjoyed playing the music of his favorite bands by ear instead. After joining his high school's jazz band, Rob was recruited by two members of a band called Karma after a concert to join their group. Thru the Karma bandmembers, he met Brad Delson and Mike Shinoda.
Eventually, Rob and Brad would form their own band called Relative Degree. Their dream was to perform at the Hollywood club The Roxy, a goal they never made, and broke up soon afterwards. After the band's break-up, Rob's life became a life of drug and alcohol. It was these hard times that took his focus away from drumming. Eventually, by the end of high school, Rob got his life back in order and began playing full-time again. Soon, he got a call from Mike Shinoda asking him to join his and Brad's band, Xero.




