Bob Dylan and Robbie Robertson at the City Lights Bookstore, San Francisco, 1965.

The two other guys are Julius and Peter Orlovsky (wearing a hat and eyeglasses). Julius had a history of mental disabilities and had been institutionalized. Peter was well-known as Allen Ginsberg's partner and lover over many decades. He was a published poet in his own right and appeared on Ginsberg's First Blues album, along with Dylan. His talents were also on display during the 1975 Rolling Thunder Revue (Dylan, Ginsberg, and a cast of dozens).