Reporters from all over the world descended on the FleetCenter a week ago Tuesday, the opening night of their "Lick" tour, to see whether the aging Rolling Stones have any gas left in their rock-and-roll tank. But for all the media hoopla, the Stones themselves — and Mick Jagger in particular — have been uncharacteristically low-key about what many have predicted could be their last ever major tour. For starters, the band aren’t promoting a new studio album. They seem to have learned over the course of their past few releases that today’s Stones fans are more interested in seeing the band play their older material live than in hearing new entries to the substantial Jagger/Richards songbook. So with the exception of the couple of new tunes they tacked on to their latest greatest-hits collection (Forty Licks, Virgin), they simply skipped the studio and went right to the stage with "Lick," which gave them a chance to dig deeper into their back catalogue for showpieces than they ever have in the past.

The result: an ambitious three-pronged tour that’s been tailored for midsize arenas like the 16,000-seat FleetCenter, massive venues like the new Gillette Stadium (where they played a week ago Wednesday), and small theaters like the Orpheum (where they ended their Boston stay on Sunday night). And, best of all, a show that lets the music do most of the talking, stripped of many of the bells and whistles that have been part of past Stones extravaganzas.

To modern concertgoers who’ve grown used to hearing bands deliver DAT-assisted live performances that sound almost as polished as a studio recording, the Stones probably seemed a bit of a mess as they cruised through a set that drew heavily on material from Exile on Main Street and Beggars Banquet. And though it would be tempting to attribute the rough edges to opening-night jitters, it would also be a mistake: even in the ’80s, when the Stones were at their most practiced, Ron Wood would occasionally stumble going into a solo, and the band were loose enough to let Keith signal when certain songs were supposed to end instead of relying on some pre-programmed cue. With little more than a fancy video screen adorning an otherwise simple stage set this time around, they seemed even looser and more willing to let happy accidents intercede. At the end of the first tune, "Street Fighting Man," drummer Charlie Watts looked a little anxious as he watched for Keith to signal the ending, and there were points during "Stray Cat Blues" when it was hard to find the backbeat among the bluesy guitar chords.

Ultimately, that’s a big part of what keeps the Stones special and their shows exciting as they enter their fourth decade in the rock-and-roll business. They surely understand that it’s the improvisational blues quality of their music that makes them viable even as Mick and Keith push 60. Nobody, after all, does the Stones quite the way the Stones do.