Video: 'Human Be-In 1967' (3 videos)

(Saturday, January 14, 1967) — The Sixties’ “Summer of Love” unofficially began today with a “Human Be-In,” a gathering of 20,000 hippies for a counterculture event at Golden Gate Park in San Francisco.

Music was provided by a host of local rock bands including Jefferson Airplane, The Grateful Dead, Big Brother and the Holding Company and Quicksilver Messenger Service.

The event also included performances by poet Allen Ginsberg, comedian Dick Gregory, activist Jerry Rubin and psychologist and LSD advocate Timothy Leary, who urged the audience to “turn on, tune in, and drop out.”