Question: Who was the name of the bassist featured on  the American rock band Weezers most successful studio album?
Sentence (from "Weezer discography"): The album was a huge commercial success, peaking at number 16 on the US "Billboard" 200 and spawning the singles "Undone – The Sweater Song" and "Buddy Holly", both of which were responsible for launching Weezer into mainstream success with the aid of music videos directed by Spike Jonze.
Relevant evidence: Yes