Pink Floyd were founded by students Syd Barrett (guitar and lead vocals), Nick Mason (drums), Roger Waters (bass and vocals), and Richard Wright (keyboards and vocals). Under Barrett's leadership, they released two charting singles and a successful debut album, The Piper at the Gates of Dawn (1967). Guitarist and vocalist David Gilmour joined in December 1967; Barrett left in April 1968 due to deteriorating mental health. Waters became their primary lyricist and thematic leader, devising the concepts behind the albums The Dark Side of the Moon (1973), Wish You Were Here (1975), Animals (1977), The Wall (1979) and The Final Cut (1983). The band also composed several film scores.