Having released their first record in 1967 when Syd Barrett was chief composer in the ranks, Pink Floyd followed this generally praised work with a move towards prog-rock experimentalism, and after Barrett agreed to leave the band before the release of their sophomore album, the group - now with Dave Gilmour filling the hole Syd's departure had created released a couple of records which even the band themselves were somewhat less than happy with. However, by 71 the group were really gelling again for the first time since Barrett's demise, and with Gilmour emerging as a shaping force the album they now started recording was ultimately seen as the zenith that they had been striving for. 1971 was the year that the post-Barrett Pink Floyd became the band they were destined to become and it was during this period in which the flood of classic albums that would continue through to the Floyd's ultimate floundering following the departure of Roger Waters in the early 1980s, begun. This film reviews this period in detail and considers again the band's live performances and studio recordings, as well as their lives and career generally, shedding fresh light on how Pink Floyd became one of the biggest bands ever. Includes archive interviews with the group, rare and studio performance footage, plus contributions and insight from those who worked alongside the group in this defining period.