ROCK MUSIC BECAME the most important medium for defining and coalescing the new hippie aesthetic, and the style that emerged with the brilliant, swirling colors and hallucinogenic imagery was called psychedelic. Bob Dylan showed how meaningful songs with surrealist imagery could be wedded to popular music. Though he was one of the few artists who did not jump on the psychedelic bandwagon, his then revolutionary efforts inspired countless bands who did. The first psychedelic bands came from San Francisco: the Grateful Dead, Jefferson Airplane, Big Brother and the Holding Company and others; but it was not long before the psychedelic aesthetic spread to musical groups in New York such as The Fugs and the Velvet Underground, to soul groups such as Sly and the Family Stone and the Chambers Brothers, and to England where the Beatles, the Rolling Stones and others began producing albums of psychedelic music, often with overtly psychedelic covers.