From 1969, this was their fourth album and they had all their tricks in the bag. Insert all the drug jokes and references you want, this album is a masterpiece – one disc studio, one live. After it was released in November 1969, the decade was done.
The music was written mostly by David Gilmour and Rick Wright; lyrically, the album deals with themes of communication. Recording took place in several locations, including the band's Britannia Row Studios, and Gilmour's houseboat, Astoria.