When a bleary Jimmy Page, Robert Plant, John Paul Jones, and Jason Bonham formed a sweaty scrum, soaked up the adulation of 22,000 fanatics, and left London's O2 Arena stage after 130 minutes on December 10, 2007, the logo still remained.

LED ZEPPELIN.

Colossal. Stark white on black. Towering over mortals from 50 countries, some who had paid thousands for a $250 ticket (20 million applied for the official lottery). That vaguely mystical script, combining two appropriately named, late-19th-century fonts -- Quaint Gothic and Virile -- so familiar from jean-jacket patches, tube tops, bumper stickers, and rock's very firmament. The message: Led Zeppelin, more than any other band in popular music history, will awe you, bewitch you, overpower you, humble you, and leave you pennilessly grateful for the ravaging. Even at three-fourths strength, after a two-decades-plus break.

And yes, the wizardly white-haired Jimmy Page, who sculpted a gnarled, keening scree out of his 1958 Gibson Les Paul, is 64 bleeding years old. I jadedly thought I'd experienced this sort of overwhelming sonic spectacle before. The Butthole Surfers' nakedly fiery, smoke-choked, freak-punk convulsions in the '80s. The Chemical Brothers' ecstatic, beat-bludgeoning rave sorties in the '90s. Radiohead's rumbling, hypnotic quaver in New Jersey's Liberty State Park pre-9/11, with the World Trade Center towers looming across the Hudson River. But none of the above have sold more than 300 million albums worldwide or trademarked hard rock and/or heavy metal by elevating every single instrument to a riff fountainhead and, as a result, provided the soundtrack for three generations of teenagers to experience life's hormonal, sacramental, and morally dubious extremes. That can't help but add an extra tingle.

You know that bit from the trashy biker movie The Wild Angels that Primal Scream sampled on Screamadelica? When the delirious dude testifies: "We want to be free! We want to be free to do what we want to do! And we want to get loaded. And we want to have a good time! And that's what we're gonna do. We're gonna have a good time. We're gonna have a party!" That's Zeppelin. With the blustery, searing blues squall of their first two albums, they deflowered the bewildered children of '60s idealism; and with the volatile baller barrage of their infamous arena tours, they monetized and strip-mined '70s hedonism and violence, inspiring the punk backlash, the hair-metal backlash, the grunge backlash, the rap-rock backlash, and the White Stripes backlash, as well as foreshadowing rap's most outrageously priapic forays into world domination.

The phrase "Do What Thou Wilt" is written on the runoff groove of the original vinyl pressing of 1971's Led Zeppelin IV (a reference to occultist Aleister Crowley). And thanks to Zep, that's been our definition of rock'n'roll ever since.

But armchair history aside, what about the music? Can a band's songs, which are not just thematically, but rhythmically, based on the transcendent, childlike desire to push shit too far, genuinely resonate when played by men old enough to be some of their current fans' grandfathers? Were the three surviving original members, who hadn't played a full set together in 27 years, just the Stooges with fuck-you money?