In 1991, Morello was looking to form a new band after Lock Up disbanded. Morello was impressed by Zack de la Rocha's freestyle rapping and asked him to join his band. He also drafted drummer Brad Wilk, who he knew from Lock Up, where Wilk unsuccessfully auditioned for a drumming spot. The band's lineup was completed when Zack convinced his childhood friend Tim Commerford to play bass. After frequenting the L.A. club circuit, Rage Against the Machine signed a record deal with Epic Records in 1992. That same year, the band released their self titled debut. They achieved a considerable amount of mainstream success and released three more studio albums.