Pink Floyd's hallucinatory presentation of lights and music at London's Roundhouse in 1966 brought psychedelia to the U.K. scene. The group carried rock and roll into a dimension that was more cerebral and conceptual than what preceded it. What George Orwell and Ray Bradbury were to literature, Pink Floyd is to popular music, forging an unsettling but provocative combination of science fiction and social commentary. In their early years, with vocalist, guitarist and songwriter Syd Barrett at the helm, Pink Floyd were the psychedelic Pied Pipers of the "London underground" scene. In the Seventies, with bassist Roger Waters providing more of the songwriting and direction, Pink Floyd became one of the most influential rock bands of all time.