They wanted Muddy to do that scene in the street, but didn't want any white guys in it. Bob and Jerry (guitar, harmonica) are white. Muddy told the producers, if they don't want his boys, they don't want him, so they called John Lee Hooker. That is the rest of Mud's band backing him up, with the addition of Walter Horton on harmonica. So yeah, Muddy Waters was a real racist. Haha!