Forty years after Britain's foremost 'underground' band released their debut album, 'Piper At The Gates Of Dawn', Pink Floyd remain one of the biggest brand names and best-loved bands in the world. This film features extended archive footage alongside original interviews with David Gilmour, Roger Waters, Richard Wright and Nick Mason, and traces the journey of a band that has only ever had five members, three of whom have lead the band at different stages of its evolution.