Madonna,Wembley Arena, London

'Ladies and gentlemen," she says, coyer than a carp, "thank you for coming to my little show..." Little? Everything about Madonna's 2006 tour is big. Not as record-breakingly big as the advance hype would like you to believe (a mere eight nights at Wembley, next to Busted's 11), but pretty damn huge all the same.

The biggest thing about it, of course, is the ticket price. The pheasant-shooting, fur-flaunting, rambler-suing Queen of Pop is already notorious for taking... well, for the sake of politeness let's say "liberties" with the admission charge, but she's surpassed herself this time. Where I'm sitting, it's £160 a seat, and even the poor souls watching from the distant corners of the arena have coughed up £80. "Supply and demand, pure and simple," the free marketers would say, but demand, in this case, has been cattle-prodded by chatter - probably mendacious, probably planted - that this may be Madonna's last-ever tour.

And of course, it's worked. Wembley is packed to the rafters with rich straights, rich gays, and rich tourists, and is buzzing with excitement for an hour beforehand. I don't mention "the rafters" figuratively, by the way: a pair of pigeons have snuck in to watch the show. I want to warn them "Look out, she might be armed!" but they'd never hear me above the shrieking.

And is it worth it? Well, when a giant mirrorball descends from the ceiling like a spaceship, lands on a podium in the middle of the posh seats, splits open like a chocolate orange, Madonna steps out in a top hat, begins womanhandling some bondaged-up minions with a riding crop, and segues "Future Lovers" into Donna Summer's "I Feel Love" (the song it shamelessly plagiarises), you'd have to be terminally unimpressable, or a liar, not to concede that it's a pretty damn superfly opening. Then there are suspended walkways, a bucking bronco on a rotating pole, gymnastic apparatus, and acrobatic dancers in horses' manes and Gaultier costumes.

During a lull in proceedings, a picture of a small girl's face appears, with a voiceover saying, "I was gasping for air, trying to release my father's fingers from my throat". Suddenly, Madonna rises out of the floor, crucified on a mirrored cross, and starts singing "Live to Tell". It occurs to me that, had I walked in late and had this had been the first thing I'd seen, I'd most likely have wet myself laughing, so stereotypically "look-at-me-being- shocking" and Madonna-esque, is the gesture. Over her head, there's a film about Aids orphans in Africa. Is she making a bold statement about Vatican policy on contraception here? Is the juxtaposition of crucifixion and child mortality aimed at Papa Ratzi? We'll never know, because she doesn't have the balls to spell it out. "The world is full of people who talk the talk..." she says later, "but how many of us really walk the walk?" Well, quite.

And herein lies the problem with this show, and Madonna's career in general: it's filled with crass, fatuous, mindless symbolism but precious little meaning. Tonight we see Jewish and Arab "blood cells" intermingling with yin and yang signs, we see the daft Kabbalah band round her wrist, we see dancers goose-stepping and Nazi-saluting through "Ray of Light", we see a montage of Hitler, Nixon, Mao, Bush, Bin Laden and Blair (the prime minister is actually cheered, which tells you plenty about the kind of people who'll stump up £160 to watch Madonna). At the end of the sequence, the words "Is anyone listening?" appear on the screen. A more pertinent question would be, "Listening to what?" If you're feeling charitable, you can call it Pop Art. If you're not, you can call it repeatedly reaching for High Culture and falling woefully short.

Admittedly, there's still much to enjoy. For a start, it helps that Madonna's album Confessions on a Dancefloor is a late career best. This is largely the work of her musical director Stuart Price, aka Jacques Lu Cont of Les Rythmes Digitales, who coordinates proceedings from the shadows, looking like the man from the Milk Tray ad.

The show is broken into four acts: "Equestrian" (complete with self-referential MRI scans and x-rays from her own tumble from the saddle) is the first; "Bedouin" (complete with a chap from Yemen blowing through an antelope horn) is the second. The third is entitled "Never Mind the Bollocks", although her attempts at being punky are embarrassing: falling to her knees with her guitar, looking less like Iggy, and more like Charlie Dimmock forking the herbaceous border. Her attempts at being sexy - a hard habit to break - are worse. When she takes her top off, or shoves her hand inside her pants, I involuntarily think of the gran who gets her toes sucked in Little Britain. For the "Disco" finale she struts about in a white Saturday Night Fever suit as "Disco Inferno" morphs into "Music", and dons a "Dancing Queen" cape as "Lucky Star" morphs into the Abba-sampling "Hung Up" (see what she did there?). But not before she's had a sit down, and tried to apply the common touch.

"I never thought I'd say this about London," she says, before saying something she always says about London, "but it's good to be home. I miss the city, I miss the country, I miss my home, I miss my horse, I even miss the Congestion Charge... just kidding, I'll never miss the Congestion Charge!"

In heaven's name, do us a favour. With the proceeds from tonight's show alone, Madonna could afford to park a thousand-strong fleet of Bentleys in London's congestion zone from now until Doomsday.

s.price@independent.co.uk