Who is the only member of Pink Floyd to be featured on every one of their albums and the only constant member of the band since its formation in 1965?

Nick Mason is the only member of Pink Floyd to be featured on every one of their albums and the only constant member of the band since its formation in 1965.

Pink Floyd was founded by students: Syd Barrett on guitar and lead vocals, Nick Mason on drums, Roger Waters on bass and vocals, and Richard Wright on keyboards and vocals. They gained popularity performing in London's underground music scene during the late 1960s. Guitarist and vocalist David Gilmour joined the band in December 1967 when Syd Barrett's behavior became increasingly erratic and unpredictable, partly as a consequence of his reported heavy use of psychedelic drugs.

Syd Barrett was dropped in 1968 due to deteriorating mental health. Following creative tensions, Richard Wright left Pink Floyd in 1979, followed by Roger Waters in 1985. David Gilmour and Nick Mason continued as Pink Floyd. Richard Wright rejoined them as a session musician and, later, a band member. After nearly two decades of animosity, David Gilmour, Richard Wright, and Nick Mason reunited with Roger Waters in 2005 to perform as Pink Floyd in London as part of the global awareness event Live 8.

Pink Floyd, under Barrett's leadership, conceived their debut album, The Piper at the Gates of Dawn (1967). Roger Waters became the band's primary lyricist and conceptual leader for their successful albums The Dark Side of the Moon (1973), Wish You Were Here (1975), Animals (1977), The Wall (1979) and The Final Cut (1983).