For several months, he and songwriting partner Mick Jagger have pored over 40 years of music-making, preparing for a tour that requires them to put on different shows depending on whether they're in stadiums, arenas or theaters. They've worked up around 130 songs they've rarely played live to complement the crowd-pleasers the Stones have done more or less on autopilot since the '70s.

For musicians whose average age is 58, and whose last several tours have been scripted down to the last spotlight cue, this qualifies as a risky proposition. Even with TelePrompTers.

"So I'm standing around at rehearsal," Richards says by phone from Boston, his voice a tad more animated than its usual gravelly growl. "And there's this big canvas board where Ronnie has written down all the songs.

"I'm looking at it going, 'What are we studying for, Mr. Memory of the Universe? At our age?' This is crazy."

Then Richards drops into a whisper. "Strange thing, though. Even with a song I hadn't played in 20 years, if I didn't think about it and just started, my fingers knew where to go. Right away, like it was automatic... . Comes down to something very simple: Don't think, just feel."

Which, of course, has always been the Rolling Stones' credo, and one reason this band of jazzheads and blueshounds still merits attention.

Its core musicians - Jagger and guitarist Richards, both 59, drummer Charlie Watts, 61, and guitarist Ron Wood, 55, who get tour assistance from keyboardist Chuck Leavell, bassist Darryl Jones, a horn section and background singers - hail from the golden age when feeling mattered more than the twisted intellectual constructs that choke the music now.

The Stones bear some responsibility for the level of contrivance associated with contemporary pop - they are, after all, the fathers of stadium-size spectacle. But they also have contributed their share of anarchy. And there remains the chance - OK, just a glimmer - that on some starry night the Rolling Stones will tear up the script and flatten everyone within earshot. So we stand in line, spend crazy money for tickets, and do things we wouldn't do for any other reunion tour.

If late-in-the-game greatness is even a remote possibility, it's largely because of Richards, the rock iconoclast who elevated not giving a damn to an art. Where Jagger obsesses over every ripple of his image, Richards is the same heedless cat he's always been, a walking example of instinct over intellect. His specialty is the pointillist rhythm-guitar riff, and for an incredibly long time, he has supplied the world with two-bar motifs that distill rock to its rebellious essence. The chordal blasts he has lodged into the cultural memory - not just "Satisfaction," his War and Peace, but "Brown Sugar," "Jumpin' Jack Flash," "Street Fightin' Man," the list goes on - are expressions of angst and anger and rollicking joy so elemental (and universal) as to virtually define the emotional range of rock-and-roll.

Richards takes little credit for them - "I've always trusted me intuition, always listened to the voice inside" - and maintains that he knows by feel whether a Rolling Stones song is any good.

"Look, this music has been with us since the caves," he says with a chuckle. "It's very ancient music, a beautiful reaffirmation of melody and rhythm."

And he proudly notes that the Stones are big in places such as Indonesia: "If you can sell a song there, where people have no idea what you're talking about, that tells you what you're doing is beyond language."

As Richards talks about preparations for the band's Licks Tour and looks back over the Stones' astounding career, he sounds as if he's got something to atone for. He regards the current sojourn, which will continue with sold-out shows at the First Union Center on Friday and the Tower Theater Sunday, as a chance for the band to shed the larger-than-life excess, and give back to diehard fans who have suffered through greatest-hits show after greatest-hits show.

"I said it for years, and finally they listened to me: Playing in smaller joints helps us do the bigger ones," Richards asserts. "There's a lot of improvisation and adapting that goes on when you're just playing and not doing the big stadium thing."

Richards describes his relationship with Jagger as "complicated." He says he was dismayed when Jagger was knighted by Queen Elizabeth in June. He felt it distanced the band from its scrappy roots. And he adds that he's been able to endure only the first three tracks of Goddess in the Doorway, the solo project Jagger released last fall.

But he's also got enormous affection for Jagger. "There's this amazing spark of total opposites that we have, and, like many people, Mick has lots of sides, not just the one he shows the world. I think we've proven now that yin and yang can hang."

Richards believes that there's another reason the Stones are "firing hotter than we ever have this early on": Ronnie Wood, who has had bouts with substance abuse over the years, checked himself into alcohol rehab this year.

"Who am I to talk?" Richards says, making reference to the cycle of high living, dissolution, and paying the consequences that has defined his life. "Ronnie was getting a bit out there, and to his credit he recognized it himself. I've been amazed at his focus. He's really helping us forge this immense machine."

Relearning old songs, and listening to newly remastered early works - all recently rereleased on the Abkco label - has made Jagger and Richards realize that there were many neglected gems in the Stones discography. The band is performing "Slave" for the first time in 20 years, "Heart of Stone" for the first time in 25 years, and "Can't You Hear Me Knocking" and "She Smiles Sweetly" for the first time ever.

"What's weird about the record business is how sometimes you write a song, and if it's any good, you record it... . Maybe you go on to the next hit and forget about it. Meanwhile the song never stops growing. All this time later, you bring it out and it can tell you something new. That's been amazing."

This tour marks the first one without an album of entirely new material to plug. Initially, that troubled Richards greatly: The guitarist insisted that the band at least try to write and record something, even if its efforts never saw the light of day. Four tracks from sessions earlier this year appear on the two-disc hits compilation Forty Licks, which will be released Oct. 1.

Richards explains that working on new music is the best way to get the Rolling Stones revved up. "When we went into the studio, we hadn't played in three years. Nobody knows the [new] song, so the playing ground is level. There's a little bit of extra concentration, and no faking it. You start sparking off each other, and pretty soon you have something that sounds like the Rolling Stones."

He's asked whether it's harder to whip up something that sounds like the Rolling Stones these days - if the band's age and status are insurmountable hurdles. They certainly don't need to tour to send their grandkids to college. Or to earn some special distinction in the record books.

So what motivates them to go through the trials of the road?

"You know, there are demons in me, 47 at last count, and the only time they get out is when we're on stage," Richards says wryly.

So, when people see him perform, a man immersed in the work of tending a groove, does that accurately reflect what is going on inside?

"You're feeding off the music and the audience at the same time. It's a good exchange of adrenaline. Like I said before, you're not thinking. Then you'll get to something like 'Jumpin' Jack Flash,' which is my litmus test.

"It's very tight to play, the band really has to become this one sound. When it does, don't kid yourself: That's an addiction... . The riff is just beautiful. It's just flying off your fingers, and everything's easy... .

"Pretty soon you realize you're 34 feet off the ground, levitating. It's like going back to your youth. No, it's better than going back to your youth."

He stops to laugh, as though he's just divulged too much. "Then, of course, the only thing you worry about is the landing."