It's only rock 'n' roll - but it isn't, is it?

The music business is about commerce as well as entertainment, and the Rolling Stones are one of its biggest multinational firms.

There's plenty of both art and business in Exhibitionism, a vast exhibition that covers 1,850 square meters of London's Saatchi Gallery with five decades of Stones history.

The more than 500 artifacts, borrowed from the band's archive and from private collectors, include musical instruments, lyrics, sketches, film clips, outfits, posters, album artwork and stage designs. There is even a fake donkey.

From entertaining to excess, the Stones rarely do things on a small scale.

"In the end, we had over 25,000 things to choose from," says Australian rock promoter Tony Cochrane, the show's executive producer.

"I knew the Rolling Stones had a warehouse where they had kept a lot of their personal artifacts, memorabilia, famous instruments and the like," he said on Monday, a day before the show's public opening. "But no one could have known how enriched the collection was."

The result is a treasure trove for fans, who can ogle at everything from a marabou-feather cape Mick Jagger wore to sing Sympathy for the Devil to a Maton guitar owned by Keith Richards whose neck fell off during the recording of Gimme Shelter (the song ends with a barely audible clunk).

Even casual fans will likely be impressed by the exhibition's attention to detail. It opens with a life-size recreation of an apartment the band members shared from 1962-63 in Chelsea, a then-raffish, now-affluent London neighborhood.

"It was a hovel," Richards says on a recording, and the recreation captures the peeling wallpaper, mold-stained walls and unmade beds, dirty dishes, empty beer bottles, broken eggshells and overflowing ashtrays. It even smells.

Exhibition curator Ileen Gallagher says the band members were "pretty astonished" by the result.

Another room features a recreated recording studio, based on Olympic Studios in London, where visitors can watch footage of the band at work and listen to recordings of the Stones and their collaborators talking about the creative process.

The exhibition's strength is the space it gives to the band's creative partners, from backing vocalists and session players to the artists and designers who helped forge the Stones' brand image and iconography.

And, of course, there is fashion.

The Stones quickly left behind the matching checked jackets of the early '60s to forge their own style, and the exhibition shows off many of Jagger's more outrageous fashion statements, including the white dress he wore at the band's 1969 Hyde Park concert and a pair of glittery '70s jumpsuits.

Exhibitionism runs through Sept 4, with an international tour planned to follow the London show.