Farrell was a member of a Christian punk/ska band called Tasty Snax. While he was at the college, he shared the room with his friend Brad Delson, and they practiced together.
He had to go in tour with the Tasty Snax so he could not play with Delson and his band. Then, Farrell left his band to play bass with Linkin Park. Farrell's band mate Mark Fiore became Linkin Park's videographer.