By 1966, heavily under the influence LSD and Barrett, the group began to incorporate light shows to add to the psychedelic effect of their live performances. In 1967 they signed with EMI records and released The Piper at the Gates of Dawn. It is considered to be one of the best British psychedelic albums, second only to The Beatles Sgt. Pepper's Lonely Heart Club Band album.
Sadly they would never even have a chance to recreate a similar masterpiece, solely because Barrett's involvement in the band was in its final stages. Barrett was becoming heavily involved in mind-altering drugs like LSD and was showing alarming signs of mental instability. They tried to work out an arrangement where newly hired guitarist and close friend David Gilmour would perform live with the band while Barrett would make his contributions in the studio. This didn't work. Syd Barrett left the group to pursue a solo career.
The band decided to continue on without Barrett and Waters stepped in as the dominant composer and writer. Using Barrett's vision as an obvious blueprint, but adding a more formal, somber, and quasi-classical tone, their 1968 follow-up A Saucerful of Secrets, made the British Top Ten and proved the band was to continue on. For the next four years they would work on their sound, keeping it within the range of psychedlia, but reaching out to the uses