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 20,000 square feet (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 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," said 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 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 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 in 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, the dirty dishes, empty beer bottles, broken eggshells and overflowing ashtrays. It even smells.

Exhibition curator Ileen Gallagher said the band members were "pretty astonished" by the result. "Although Mick said it wasn't quite that messy.'"

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.

A whole room is devoted to John Pasche's lips-and-tongue Stones logo, inspired by a picture Jagger had seen of the Hindu goddess Kali. Another features the band's huge-scale set designs, and a third showcases album-cover imagery by artists including 1960s photographer David Bailey and Andy Warhol, who designed the infamous zipper cover for "Sticky Fingers."

"They've always managed to work with artists that have cultural significance," said Gallagher. "That's very important — and it's very astute of them."

And, of course, there is fashion. The Stones quickly left behind the matching checked jackets of the early 1960s 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 1970s jumpsuits.

Gallagher said the goal was to tell the Stones story "in a way that really brings in the cultural, artistic, historical influences of the band."

After their dose of culture, most visitors will leave through the gift shop, a reminder that this exhibition is a savvy commercial enterprise. Fans can buy everything from coffee mug for 10 pounds ($14) to a Stones-branded table football game for 4,750 pounds ($6,800). There is even a tie-in with upmarket pottery firm Wedgwood, offering delicate tea cups and saucers carrying the exhibition's less-than-delicate logo: the Stones lips emblazoned across on a bikini-wearing crotch.

A sign notes: "Over 250 years of history make Wedgwood a truly iconic English brand." Much like the Stones themselves.

"Exhibitionism" runs to Sept. 4, with an international tour planned to follow the London run.