This film explores and reviews the trip Pink Floyd took, from their mid-60s inception, when the iconic Syd Barrett led the group, through Syd's enforced departure and David Gilmour s installation as lead guitarist and co-composer, and onto the early 70s when albums like Ummagumma, Atom Heart Mother and Meddle pointed the way for Dark Side Of The Moon to enter the musical fray and the public consciousness in one fell swoop. Although its original release took place more than 45 years ago, Pink Floyd's 1973 album, Dark Side Of The Moon, remains the band s magnum opus, their piece de resistance, and their most prominent, best-known, best-selling and best-loved work. And although Floyd - in their classic line-up - had pretty much disintegrated a decade after Dark Side, the individual former members would, to this day, nary risk a solo-performance without dipping a musical toe - or several - into Dark Side's track-list. Featuring seldom seen studio and performance footage, rare archive interviews with Floyd members, contributions from those close to the group - including Pink Floyd producer Norman Scott, Soft Machine s Hugh Hopper (a close confidante of the group), Peter Banks from Yes, esteemed music critics David Stubbs, Mark Blake and Toby Manning, author of The Ambient Century, Mark Pendergast, and a host of other expert speakers - plus rare photographs and location film, promotional material and lots more besides.