One of the most influential rock acts of all-time, the psychedelic rock outfit Pink Floyd was formed in 1965 by Roger Waters, Nick Mason, Richard Wright and Syd Barrett. With Barrett as its front-man the band released its first album, The Piper at the Gates of Dawn, in 1967 to modest success. When Barrett left the band a year later, Waters took over as conceptual leader, sharing lead vocals with recently added guitarist David Gilmour, and catapulting Pink Floyd to mass commercial and critical acclaim. With this lineup, the band released its iconic 1973 album The Dark Side of the Moon, exploring themes of time, mental illness and greed and setting a new standard for textural experimentation in rock music. Although Pink Floyd played its last show in October of 1994, the band continues to inspire modern psychedelic and progressive rock music.