This was probably the most controversial concert of Pink Floyds career. Despite local protests, they were allowed to play a free concert from a barge in the lagoon opposite St Marks square, from where an estimated 200,000 people watched. The concert was nearly cancelled on July 13th when the city's superintendent of monuments claimed that the vibration could damage buildings. To pacify critics Floyd played at a reduced volume, but there were still claims of damage to marble cladding after the concert. Lamp posts were also broken by fans climbing them for a better view.

Shortly before the band released Atom Heart Mother, the band performed their current set for the cameras of public broadcasters KQED. The original master was thought to have been lost and the surviving footage has long been the preserve of bootleggers. This is the first time KQED has given their official consent to the release of the footage - essential viewing for any Pink Floyd fan.