Lead singer and guitarist of the band Reeve Oliver, and current bassist/backup vocals of the band Yellowcard. He joined Yellowcard in summer 2010 for their reunion after a 2 year hiatus. During the hiatus him and Yellowcard frontman Ryan Key formed a side project band called Big If in which Sean was co lead singer. He also used to be in a band called Dogwood but left because he felt the songs he wrote didn't fit the band's style