The four skinny guys jamming on Sly and the Family Stone’s “Thank You (Falettinme Be Mice Elf Agin)” in the Greenwood College School gym in Toronto are no freshmen. This is old school: Mick Jagger, Keith Richards and Ronnie Wood slash guitars while Charlie Watts hammers a crisp beat.

The vibe in this makeshift rehearsal hall intensifies as Jagger kicks off “Sympathy for the Devil” with a piercing “Ow!” – a Pavlovian trigger encoded in baby-boomer DNA.

OK, it’s only rock ‘n’ roll. But when the Rolling Stones roll it out, the genre gets an invigorating kick – in concert revenue, nostalgic bliss and an infusion of raptor-rocker bits for late-night comics.

The only rock-era band to sustain superstar status through five decades of spasmodic pop trends, the Stones maintain a unique standing in an industry accustomed to fast flameouts and shelved icons.

While a few hipsters and dinosaurs are struggling to attract audiences this summer, the Stones hit Boston’s Fenway Park today to launch “A Bigger Bang,” a world tour that already has sold out 98 percent of available tickets and is expected to clobber all rivals before it closes in 18 months.

The band’s only competition: itself. Since 1989, the Stones have grossed $1.125 billion internationally. In the ‘90s, the group took in $751 million and sold more than 12 million tickets worldwide, more than any other act.

“The Rolling Stones are far and away the most successful touring entity in the history of mankind,” says Ray Waddell, senior editor at Billboard.

“The Stones have written and rewritten the book on touring. The things they have brought have been pioneering, from being the first to use credit cards at (merchandise) stands to a one-promoter global tour. They are the kings.”

For 43 years, the Stones have resisted rock’s customary trajectory of rise, peak and swan dive. Even the band is amazed by its longevity.

“I remember a sense of doom when our first record got in the top 20,” Richards says. “It was conventional wisdom at the time that it would all be over in two years.”

Instead, the group generated a generation’s worth of rock classics. And when record sales waned, concert crowds ballooned to record-setting levels. The 1994-95 Voodoo Lounge juggernaut is still the top-grossing ($319.5 million) and best-attended (6.4 million tickets) tour ever.

Yet pundits speculate that this outing could be that last time, and detractors say a farewell is overdue, presumably because the Stones did not fade away. They rode out punk, survived disco and even stayed past the last call for hair bands.

Way past. Richards is 62. Jagger is 61. Watts, fully recovered from throat cancer, is 64. Wood is the baby at 58.

Predictably, the Bang announcement brought fresh rounds of codger gags. Jay Leno dubbed the trek “The We’re Grateful We’re Not Dead Tour.” David Letterman cracked, “They’re part of the Living Will-Palooza Tour.”

The ribbing hasn’t stopped since the “steel wheelchair: jokes during the “Steel Wheels” tour in ‘89, but Richards says he has been shrugging it off since the Sex Pistols slagged them in the late ‘70s.

“Look at them now,” he sneers, slouched on a black sofa in a classroom converted into a sinister retreat with black drapes, incense and glowing candles.

“We’re on the cutting edge,” he says. “Nobody’s been here before, and it’s kind of an adventure.

“They wonder why we’re still here. Well, why not? We’re a great band. We love to play. If there’s that many people who love to hear us, what’s the beef? I intend to get a lot older and a lot more wrinkled. So sharpen your pen.”

Jagger, sipping tea in his cheerier quarters, is amused by one-liners and the tired trick “of adding up all our ages, a mathematical feat beyond most people.”

He says mockingly: “I’ll do your show, David Letterman, and you come do mine.”

The Stones roll with the punch lines and always get the last laugh: millions of customers.

Says Jagger: “We wouldn’t tour unless someone said, ‘Look, there are a lot of people who want to see you.’ I always say, ‘You sure?’ “

Jagger readily agrees that rock is youth’s playground.

“You wouldn’t want only old people to do it,” he says. “It would be awful. But if you have creative energy, age doesn’t matter. Lucian Freud and Francis Bacon painted with energy late in life. The Rolling Stones kept their creative forces, maybe because we don’t make records every 10 minutes.”

“A Bigger Bang,” their first new album since 1997’s “Bridges to Babylon,” arrives Sept. 6 amid far less hoopla than the tour.

Critic Lester Bangs branded 1976’s “Black and Blue” as “the first meaningless Stones album,” and fan fervor has been shrinking with subsequent new records. The band has sold 20.9 million albums since SoundScan began tabulating in 1991 with buyers favoring oldies: 2002’s “Forty Licks” sold 2.5 million, double the take for “Bridges to Babylon.”

Yet a positive buzz is building for the 16-track “Bang,” a raw rocker co-produced by Don Was. An early review by England’s Uncut declares: “The Stones have defied the odds and raised their game to produce (a) great album.”

Its wide range of romantic and social topics embraces heartbreak and humor, regret and revenge.

That breadth comes easier with experience and, yes, age, Jagger says.

“When you’re young, you tend to be angry a lot,” he says. “Later, you’re able to express diverse emotions.

“I do draw from my life. But sometimes I don’t know who it’s about. And you have to be inventive. You draw on memories, you observe other people, and you embroider.”

Jagger and Richards, who toiled independently and often testily on “Bridges,” bonded on “Bang” after learning of Watts’ cancer diagnosis last summer.

“Necessity put it together,” Richards says. “Mick got on drums. I doubled on bass. We sent songs to Charlie while he was recuperating. It’s been years since Mick and I worked this closely together.

“There is no clear plan until the music is telling you what to do. It yelled at us, ‘Do not overproduce me. Do not put the icing and the marzipan and the candles on.’ “

Jagger adds: “We did this record with minimal technology, just suitcases of computers. I didn’t want to go into a massive glass-and-stone $10 million studio with all the bells and whistles. All that technology can change the way you play. We pared it down, and the intimacy worked.”

Despite clashing approaches, they collaborated peacefully and made room for each other’s pet sounds. Their teamwork “has changed a lot,” Jagger says: “Keith was very supportive of my songwriting, guitar-playing, bass-playing, drumming.”

Meaning he wasn’t in the past?

“Obviously not!” Jagger says with a laugh. “It’s a long-lasting collaboration, but we do have separate ways of doing things. I’m quite analytical: I want this groove. Keith likes to play a tune a lot until something happens.”

Richards says the media’s fisheye has turned their infrequent tiffs into epic battles.

“There’s this perception that Mick and I are always fighting,” he says. “Most of it is very smooth sailing. Every time we stumble across the odd spat, everyone hears about it.”

For now, they’ve formed a united front to make sure everyone hears about the new album and tour. That means new sponsorships to subsidize the tour and maximize exposure, including a partnership with ABC and the NFL for season-long promos on Monday Night Football, starting with footage from a Detroit show for a pregame special Sept. 8.

Immune to criticism of their corporate tie-ins (a fixture since 1978), the Stones make no apologies to the purists who call the band a sell-out.

“It’s super-competitive out there,” Jagger says. “There’s a lot of tickets to move, and this is a way to create excitement for the tour. It’s capitalism. It’s America. It’s 2005.”

It’s time to head back into rehearsals, where the band is gathering for run-throughs of “Respectable,” “Live with Me,” “The Worst” and new single “Rough Justice.” A few onlookers, including Jagger’s 13-year-old daughter, Georgia, and her frisky papillon pup, Daisy, are swaying on the sidelines, but nobody’s grooving harder than the band itself.

Richards is itching for another spin under the spotlight.

“The audience is our gas tank,” he says. “You can feel lousy, it can be 102 degrees, but get on that stage and you’re cured. It’s adrenaline, endorphins and pheromones. It’s one of the biggest lifts in life.”