The thing that stops your eye is the body. A lean, tanned torso ends where it should not: at the haunches and hind legs of a dog, splayed across rough wooden boards. The face on top is unmistakably David Bowie, copper hair raked back, one gold hoop in his ear, eyes painted to hold yours with a cool, slightly feral steadiness. He props himself on one arm, the other hand resting flat, and the seam where man becomes animal is rendered so smoothly that the illusion almost holds.

This is Diamond Dogs, the cover the Belgian artist Guy Peellaert painted for Bowie in 1974: a pop star fused with an animal and set down in a smoky carnival that never quite existed. Look past the reclining figure and two more grinning creatures crouch in the shadows behind him, and the strangeness only compounds.

What the painting first showed, and what a nervous record company would not let most buyers see, turned this sleeve into one of the most fought-over objects in rock. To understand why, start with the image itself.