The shiny silver torso is a pure, beautiful, mysterious homage to the famous muse who inspired it. Abstract and geometric, it looks barely human. For years, the artist kept his model's identity secret. Only the nipples, cast directly from source, give any clues. But decades would pass before they were revealed as belonging to the rock diva Marianne Faithfull.

The sculptor Clive Barker is known for his witty chrome and bronze replicas of household objects and pop-culture icons, from fridges and cakes to Mickey Mouse and Homer Simpson. A former Vauxhall factory worker from Luton, Barker is an unassuming 67-year-old who makes no grandiose claims for his work. But critics have credited him with pioneering the lustrous, supersized kitsch style popularised by Jeff Koons years later.

As Swinging London insiders in the 1960s, Faithfull and Barker moved in similar circles. Her first husband, John Dunbar, co-owned the chic Indica Gallery, that epicentre of grooviness where John Lennon met Yoko Ono. Barker also exhibited at the Robert Fraser Gallery. Fraser was infamous himself, having been arrested at the notorious Redlands drug bust with Faithfull and her boyfriend at the time, Mick Jagger.

Barker first took a shine to Faithfull, literally and metaphorically, in 1974. They became lovers, long after she left Jagger and sank into drug addiction. When he suggested making a cast of her breasts, it was all in the best possible taste. Naturally.

“I was rather flattered,” the 61-year-old singer recalls in that gloriously pockmarked, smokedamaged voice. “It was a good line, I suppose. A good seduction line.”

Their relationship was clandestine, and Faithfull still seems coy about it today. “We had a little love affair,” she says carefully. “We weren't really a couple. Nobody knew who the model was; that's only just come out. That's the customary thing to do anyway, to not talk about the model.”

Barker had another, more practical reason for keeping his muse's identity secret. He was, after all, trying to conceal his adulterous affair from his wife of the time. But she must have twigged, I suggest, when he made further sculptures of his lover's breasts and head, explicitly identifying them as belonging to Faithfull.

“Those were done later, in the 1980s,” Barker says. “Everybody knew by then. To be honest, I think my wife knew at the time anyway. People always know, no matter how much you try and pull the wool over their eyes.”

Barker's torso of Faithfull is currently on show as part of Post-War to Pop at Whitford Fine Art gallery, in London, alongside works by Patrick Heron, Allen Jones and many more. The exhibition charts the period, particularly during the 1960s, when painters and sculptors began to become media celebrities in their own right.

Rock and visual art have long been natural bedfellows, of course. As Barker remarks, British pop was born in art school - Pete Townshend, Keith Richards, John Lennon, David Bowie, Bryan Ferry and Jarvis Cocker are just a few art students who later found pop fame.

Although they remain friends, Faithfull and Barker have not met in person for years. He stayed in London, while she now lives between Paris and Dublin. But this story does not end in 1974. Ten years after their first split, they had another brief affair, in 1984.

“She came round to make a telephone call and ended up staying for months,” Barker recalls, laughing. “Which was very Marianne.”

Post-war to Pop, Whitford Fine Art, London SW1 (020-7930 9332), May 22-June 20

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