The 1969 Cambridge photo shoot from which the Ummagumma sleeve was assembled, courtesy of Hipgnosis Portraits; that inspirational cocoa tin; Atom Heart Mother - the record label had a cow.

Aubrey Powell: "What happened with Ummagumma [1969] is that Pink Floyd were under huge pressure from EMI to have their picture on the cover. I remember Roger being very resistant, but they agreed come up with something interesting. Storm had found this packet of cocoa powder, made by a company called Droste. It had a picture of a woman holding a tray with the packet on, which had a picture of the woman holding a tray with the packet on… and so on. I shot the Ummagumma cover at Storm's girlfriend's parents house in Cambridge. But it was Storm's idea to have the picture on the wall and have them doing something different in each image - Pink Floyd as a sort of living sculpture. The lettering on the floor came from the Cambridge department store, Eden & Lily, where l'd worked when I was a student. The Gigi record was something we put there to fill the space. There was no hidden meaning. With Ummagumma Pink Floyd gave the record company what they wanted, but on their own terms. Of course for the nextalbum, Atom Heart Mother [1970], we went the other way, and gave them a cow. I still think it's a great cover and the most unusual ever.”

some of my favourite microscope images I’ve taken

Prof. Alfred Gysi, Oscillation paths