Question: When does the Zack de la Rocha's friend born who is an American musician, best known as the bassist?
Sentence (from "Tom Morello discography"): In 1991 Morello left Lock Up to start a new band, after being impressed by Zack de la Rocha freestyle rapping he invited him to join his band, he also drafted Brad Wilk who had previously auditioned as a drummer for Lock Up.
Relevant evidence: Yes