Led Zeppelin, O2 Arena, London

The arena is plunged into darkness, and an old American newscast appears on the big screen. A reporter solemnly previews the imminent arrival of Led Zeppelin in Tampa. This band, he says, is "breaking records set by the Beatles", as we see the four figures step from their private jet. "Robert Plant, he's the one with the curly hair...."

At this point, the newscast is drowned out by real cheers. I don't think I've ever heard a frisson ripple around a crowd like it does tonight when the drummer taps out the 1-2-3-4 of a snare in the darkness, before a note of "Good Times Bad Times", the curtain-raiser, has even been played.

This may officially be a charity tribute concert for Ahmet Ertegun, a pretty obscure figure if you aren't an insider or musical trainspotter, but it's those four stringy figures, or three at least and one of their offspring, who are able to break records all over again with a show of this scale and expense. The fortunate few are a mix of celebrities and real-life Tommy Saxondales. From where I am sitting, if I threw a stone, I could hit members of Pink Floyd, Oasis and Genesis.

Everyone is willing Zeppelin on to recapture, to quote second song "Ramble On", the feeling of "years ago in days of old, when magic filled the air". And, to a surprisingly large degree, they do it.

Of all the big dinosaurs of Seventies rock, Led Zeppelin were the most dementedly penile. Black Sabbath were too sunken in a depressive downer, Deep Purple too impressed with their own bigness to really strut. Zeppelin, on the other hand, were so phallus-fixated that when Robert Plant didn't have his hand metaphorically down his pants, he had it literally down his pants.

It's crucial, then, that Plant retains that swagger. And, in crotch-crippling jeans and with only a Catweazle beard between him and his Seventies appearance, he does so, kicking the base of his mic stand high over his head. He may bottle out of the high notes on "Black Dog" the part which I like to pretend goes "Hey hey, marmoset/ The way you move/Gonna Make you sweat/Gonna make you groove" but he still oozes charisma.

Nobody's foolish enough to believe that they're actually unchanged since the days of doing appalling things to groupies with a dead shark. John Paul Jones looks like a groovy schoolteacher; white-haired Jimmy Page looks like a TV magician in his knee-length suit jacket, and drummer/ heir Jason Bonham looks like a bouncer from The Jerry Springer Show. And we've all read the story about the legends demanding an ironing board backstage. Yes, Led Zeppelin are now the type of people who put creases in their Levi's.

If Zeppelin's sexual politics feel anachronistic now, then so, to a great extent, are their aesthetics: the 12-minute mystical odysseys are, to be polite, taxing on modern attention spans. When Page breaks out the double-headed guitar and pulls a face like he's sucking a Werther's Original, and Jones strokes his bass like it's an old cat, I yawn so wide I split the corner of my mouth.

On the other hand, the moment in "Dazed And Confused" when he coaxes crazy noises from his strings with a violin bow, you stop cackling at the memory of Spinal Tap, and start applauding at how mind-blowing it is that the 63-year-old can fire lightning from arthritic fingers. Jeans-pressing grandads they may be, but at their best, Page, Plant, Bonham and Jones can still burn up this dome like it's the Hindenburg.

DEATH & REBIRTH OF LED LEP:

After John "Bonzo" Bonham died of alcohol poisoning in 1980, the remaining members initially refused the idea of continuing with a new drummer. All three went on making music. Robert Plant releasing a solo album in 1982 and eight more since. The biggest myth floating around the 02 show was that it hasn't happened before. Page, Plant and Jones reunited for Live Aid in 1985, with Chic's Tony Thompson on drums, for a famously shambolic performance.