Peter Blake and Pop Music, Pallant House Gallery, Chichester

The jukebox is like a magnet – every visitor to Peter Blake and Pop Music at Pallant House in Chichester heads straight for it. "Oh, it's got 'Hound Dog!'", chirrups a woman in her seventies, who starts to dance, right there on the gallery floor, as the robotic arm picks the 45rpm disc and plops it on to the turntable of the Rock-Ola Princess. She might have chosen "Peggy Sue" or "Itsy Bitsy Teenie Weenie …"(flipside, "Don't Dilly Dally, Silly"), but it had to be Elvis, and she'd sought out an attendant to turn the juke box back on: "It got overheated earlier …".

The Princess, property of a Pallant House curator, is not only the accidental star of Peter Blake and Pop Music, it provides the soundtrack for Blake's life, and, therefore, his art. At 15, he discovered his father's extensive collection of swing records: music and visual art aligned were to became his calling card. His timing was impeccable. With his receptive ear and attraction to all things American, as an art student in search of his own style in the Fifties, as an established artist in the Sixties, he seems to have fallen repeatedly into jam.

In 1960, he recalls, he met "the Liverpool song group" the Beatles. Seven years later, he created the Sgt Pepper album cover for which he is most widely known – but he was not the first choice: Paul McCartney was warned that the original design by the collective The Fool was too psychedelic, and suggested a new commission. Enter Blake – with his then wife Jann Haworth, whose joint role in the enterprise tends to be overlooked. Neatly, her Cowboy, a trophy in Pallant House's outstanding permanent collection, has hightailed it into the Blake show, for now.

Blake has loaned his copy of the Sgt Pepper screenprint to the show and explains how possibly the most famous album cover in the world was put together. The 70 cut-out figures included regular Blake motifs – Max Miller, James Dean. The assemblage was set up and shot in a day. The next morning, the piece was broken up "somebody else took most of it", and Blake salvaged only eight figures. The project cost a walloping £2,868. Blake was paid £200.

The magpie artist cannot help collecting. In 1982, A Museum for Myself, an arrangement of objects that mean something to him, included signed photographs of the Beatles, Talking Heads and George Formby, and 470 shells in a bottle. He asked Paul Weller to bring his own memorabilia for his Stanley Road cover. Result: a bus ticket, Millais' Ophelia, a picture of John Lennon. Is it possible to step anywhere in the pop world without falling over a Beatle?

Blake, now 80, helpfully documents the process of making art, and reveals himself to be an amiable collaborator. His notes to his printer, beautifully written in an italic hand, are punctuated with the word "please". Brusquer by far was Francis Bacon, refusing to cooperate on The Who's ninth album, Face Dances, in 1981. "I told you on the telephone that I could not do this portrait for the sleeve," he snaps. "I have left the £50 in the envelope." Others were less stand-offish: David Hockney, Howard Hodgkin and Patrick Procktor (see Charles Darwent, page 55) were among the 16 artists who got stuck in on The Who cover. You sense that people not only want Blake's services, they also want to perform for this facilitator, ringmaster, band leader – the Sgt Pepper of art.

Peter Blake (01243 774557) to 7 Oct