Babyshambles, Brighton Centre, Brighton<br/>Amy Winehouse, Brighton Centre, Brighton

There are moments, one imagines, when a concert promoter sees their insurance policy flashing before their eyes, and the people at the Brighton Centre contemplating this week's double-header of Pete Doherty and Amy Winehouse on successive nights must surely have had one of them.

But, bang on time at a quarter past nine, there he is, Baby Bewes himself, shocking us all by actually getting his act together and turning up at the advertised hour and playing a show. It's almost disappointing. If your brain glazes over when you hear the latest instalment of Pete Doherty's ongoing judicial saga, you're not alone. Apparently he's on a suspended sentence for tipping a bobby's helmet with a catapult, or driving under the influence of Lockets, or something.

He's also apparently going through one of his sporadic clean-ups, and on tonight's evidence, it's a tentative so-far-so-good. He walks on briskly, with a purposefulness only slightly undermined by the peeling Elastoplast hanging mysteriously from his chin.

His nostalgia for Old Albion shows no signs of dimming. The wedges and risers are bedecked in advertisements for ancient British brands of tobacco (Gold Flake, Squadron Leader), matches (Bryant & May, England's Glory) and cigarettes (Players, Navy Cut). The spotlights are draped with faded VE-Day bunting. The Union Jack and the naval ensign hang from on high. A 1950s standard lamp stands stage-left. Betjeman's Metroland is referenced on the projector. It's echoed by the crowd, with a rash of straw boaters breaking out among the trilbies (bringing a very Flanders & Swann/Sing Something Simple feel to proceedings). Doherty himself sings "Beside The Seaside" mid-set and picks "The White Cliffs Of Dover" as his lights-up music (suggesting he saw the Sex Pistols the other week). He is, in tabloid terms, a southern smackhead Morrissey.

He could, of course, have been so much more. The famous footage in which an unknown teenage Doherty is cornered by cameramen and asked about Oasis, is beautifully poignant: with a touch of the impudence of Little Alex in A Clockwork Orange about him, he speaks of Umberto Eco, and has you wondering whether the Gallaghers ever deserved such a bright and cultured young man as a fan. Now, alas, it's Babyshambles who are not worthy of the devotion they receive. But quantity and quality are two different things. Babyshambles' arena-sized following contains a sizeable contingent of vulgar chavs, only here because "It's that Pete Dokkerty out of News Of The World who feeds heroin to kittens" (and who would now be some lifer's bitch if London had California's "three strikes" rule), who buy two pints at a time: one to drink, the other to throw. One of them hits Doherty himself. "Come and have a stage invasion," he challenges. "You'll get a better shot from here."

But in the main, Babyshamblers are an awfully well-behaved, middle-class bunch who refrain from vaulting the trestle in the lobby and looting the bar. They express their adoration by hurling gifts at him, most of which he wears jewels, scarves, Sean the Sheep and a sailor's hat and, impractically, a jumper. He puts it to one side.

Doherty can't dine out on The Libertines forever, and while his new band have at least had the decency to learn how to play, albeit in a spindly sort of way, their material is still desperately thin. "Baddie's Boogie", the one decent track from Shotter's Nation, and "Albion", the one decent track from the album before it, stand out. As far as this non-obsessed layman can tell, there are no Libs songs.

He shuffles off, and after as long as it takes him to do this, that and the other, stumbles back into an armchair for the acoustic section. He can barely keep his eyes open: clearly, the show has taken it out of him. Sucking on an inhaler, he's back on his feet for a finale of "Fuck Forever", the singalong anthem assisted by a karaoke bouncing ball on the screen.

And that's the size of it: in 2007, Doherty turns up promptly, performs professionally, and leaves. Who'd have believed it? Follow that, Black Beauty. And she does. Just. For what turns out to be her last show of 2007, although we don't know it at the time (subsequent gigs are cancelled on doctor's advice), Amy Winehouse turns up very late indeed. "Sorry sorry sorry" she blabbers, but no explanation is given.

By the time she takes the stage at 10.10pm and the promoters can breathe at last there have been boos and slow handclaps for the best part of an hour. Ever since the Birmingham debacle, this has become the deal with Amy Winehouse. Everyone's read about the furore in the papers, so now they turn up to her gigs expecting to be annoyed by how late she is, and expecting to heckle her for singing erratically. It's the fun of the fair. It's what you do.

Certain things are as clear as day. One of them is that her husband (in custody awaiting trial) is a wrong 'un. He gets pantomime boos every time Wino mentions him. Another is that a few good Sunday dinners would do her the world of good. Equally obvious, however, is that Amy Winehouse is a phenomenal talent, the only worthwhile representative of the stage-school kids currently infesting English pop. Tottering on high heels like Ab-Fab's Patsy, she's an extraordinary sight: her hair seems to grow as the rest of her withers away, and now protrudes to a surreal extreme, like Lenin's crutched buttock in Dali's The Enigma Of William Tell.

And that voice is making a similar journey. Its idiosyncrasies are becoming so pronounced that, like Dylan, it barely matters whether or not you can discern the words: it's the noise that you're paying to hear.

She puts in a full show (one hour 15 mins), sings brilliantly, interacts with the crowd, plays most of the delicious retro-soul of the Back To Black album (and not so much from Frank), no fewer than three Specials covers and a storming "Valerie" (it takes someone special to make the Zutons sound good), and provides the kind of Big Pop Thrill that you only get from looking at someone and thinking "Now that is a proper pop star."

For once, give or take a broken alarm clock, Amy Winehouse doesn't screw up. Disappointing? Not at all. Heaven forbid, but it needs to be said: we'll miss her when she's gone.