British rock (art rock) band at the forefront of 1960s psychedelia (psychedelic rock) who later popularized the concept album for mass rock audiences in the 1970s. The principal members were lead guitarist Syd Barrett (original name Roger Keith Barrett; b. Jan. 6, 1946, Cambridge, Cambridgeshire, Eng.—d. July 7, 2006, Cambridge), bassist Roger Waters (b. Sept. 6, 1944, Great Bookham, Surrey), drummer Nick Mason (b. Jan. 27, 1945, Birmingham, West Midlands), keyboard player Rick Wright (in full Richard Wright; b. July 28, 1945, London—d. Sept. 15, 2008, London), and guitarist David Gilmour (b. March 6, 1944, Cambridge).

By 1968 Barrett, who had overused LSD and was struggling with schizophrenia, was replaced by guitarist Gilmour. Without Barrett's striking lyrics, the band moved away from the singles market to concentrate on live work, continuing its innovations in sound and lighting but with varying degrees of success. After recording a series of motion-picture soundtrack albums, they entered the American charts with Atom Heart Mother (1970) and Meddle (1971). Making records that were song-based but thematic in approach and that included long instrumental passages, the band did much to popularize the concept album. They hit the commercial jackpot with Dark Side of the Moon (1973). A bleak treatise on death and emotional breakdown underlined by Waters's dark songwriting, it sent Pink Floyd soaring into the megastar bracket and remained in the American pop charts for more than a decade. The follow-up, Wish You Were Here (1975), included "Shine On You Crazy Diamond," a song for Barrett, and, though it went to number one in both the United States and Britain, it was considered anticlimactic and pompous by many critics.

By the release of Animals (1977), it was clear that Waters had become the band's dominant influence, and there was increasing internal conflict within Pink Floyd. Their sense of alienation (from both one another and contemporary society) was profoundly illustrated by the tour for 1979's best-selling album The Wall, for which a real brick wall was built between the group and the audience during performance. After the appropriately named The Final Cut (1983), Pink Floyd became inactive, and legal wrangles ensued over ownership of the band's name. Waters, who dismissed Wright after The Wall and took over most of the songwriting, was even more firmly in control. As a result the band split, but, much to Waters's chagrin, Gilmour, Mason, and Wright reunited, continuing as Pink Floyd. In the late 1980s Wright, Gilmour, and Mason released two albums, including the ponderous A Momentary Lapse of Reason (1987) and The Division Bell (1994), while Waters pursued a solo career. Waters reunited with his former bandmates for a single performance at the Live 8 benefit concert in 2005. Pink Floyd was inducted into the Rock and Roll Hall of Fame in 1996.