<preform>Babyshambles, Brixton Academy, London</br>REM, Hammersmith Apollo, London</preform>

Back in Pete Doherty's Libertines days, the thrill was the constant feeling that he and Carl Barat might have a fight onstage (or might have a kiss, such was the homoerotic frisson). Nowadays, it takes more to sustain our interest. The level of scandal - following the on-again/off-again affair with Kate Moss, those "zombie-face" and "dragon-chasing" tabloid front covers, the robbery and blackmail charge, and subsequent 10pm curfew which almost threatened tonight's gig (until the nice judge told little Peter he could stay up till midnight, as long as he was good and drank his milk), and even Tory leader Michael Howard chipping in to declare Doherty a social menace - is far higher. Nowadays, morbidly fascinated ghouls that we are, we don't just want the prospect of a fight. We want blood.

Back in Pete Doherty's Libertines days, the thrill was the constant feeling that he and Carl Barat might have a fight onstage (or might have a kiss, such was the homoerotic frisson). Nowadays, it takes more to sustain our interest. The level of scandal - following the on-again/off-again affair with Kate Moss, those "zombie-face" and "dragon-chasing" tabloid front covers, the robbery and blackmail charge, and subsequent 10pm curfew which almost threatened tonight's gig (until the nice judge told little Peter he could stay up till midnight, as long as he was good and drank his milk), and even Tory leader Michael Howard chipping in to declare Doherty a social menace - is far higher. Nowadays, morbidly fascinated ghouls that we are, we don't just want the prospect of a fight. We want blood.

The trouble is that Doherty's sparring partner isn't around any more. In fact, I saw Carl Barat only a few days ago at the NME Awards. Despite having recently recovered from a tumour operation, Barat was the life and soul, staying till the very end. Meanwhile, Doherty, who was also booked to attend, got his mother - yes, his mother - to phone in sick for him, only 10 minutes before the doors opened. The contrast could barely have been more stark, and didn't bode well for Babyshambles at Brixton.

It's to everyone's amazement, then, when Mick Jones of The Clash walks onstage at 9.45pm prompt, to introduce Public Enemy Number One himself. It's a sorry state of affairs when an audience is actually grateful that the advertised headliners have bothered to show up - for me, this is third time lucky - but such is the level of collective astonishment when Babyshambles rattle into "Killamangiro", their recent Top 10 hit, that there's utter pandemonium at the crush barriers, and unconscious human body after unconscious human body are fireman-lifted past me in a steady stream. The social menace has to turn responsible adult for a moment, and ask everyone to calm down and move back.

These extraordinary scenes of Petermania are understandable given the media hysteria surrounding the man's exploits. And the songs he wrote in The Libertines did capture the mood of a certain generation, for better or worse, and were exceptionally exciting. But this isn't The Libertines. Even during the heyday of The Libs, Doherty had the word "Babyshambles" tattooed above his nipple. This is his baby... and his shambles.

And shambles is the word. Babyshambles must surely be the most under-rehearsed, amateurish band ever to top the bill at this venue. Not that slickness and professionalism are the be-all and end-all of rock'n'roll, of course, and a certain amount of shabbiness is perhaps understandable for a band who have just lost a member (Gemma Clarke, who quit the band, citing the constant cloud of crack smoke on the tour bus as one of her reasons). But Babyshambles often sound as though they're making their songs up on the spot.

To the extent that they have a sound, it's reggaebilly, with a number of songs shifting gear from Clash-style white reggae (think "White Man in Hammersmith Palais") into Smiths-style skiffle (think "Shakespeare's Sister"), with occasional ventures into falsetto blues. When they run out of songs of their own, they throw in the occasional Libertines number, like "What Katie Did", which raises the roof with its sweet, addictive "shoop shoop de lang lang" chorus (there's a tangible relief, it must be said, at hearing something with a tune). When he runs out of those, he leads an audience singalong of "Oh My Darling Clementine", just audible above the loud creak of a barrel being scraped. He tells us he loves us. We throw things at him.

But this isn't about the music. It's the Pete Doherty Freakshow: come and look at the junkie, and see if he can stand up without falling down. In fact, he does more than stand. He leaps around hyperactively, bouncing and jiving even when there's no music, like a man on uppers rather than downers (maybe someone's changed his prescription). He's Twiggy Pop.

Without a guitar around his neck (can't play, won't play?) he looks oddly lost. He has to resort to other props, like the trilby he dons, Gene Kelly-style, for a little vaudeville dancing. That's Entertainment...

The dilemma for the compassionate, with a troubled soul such as Doherty, is whether to encourage him in continuing with his art, or whether to conclude that being in a band is only making him worse. But the dilemma for the critic is only whether his art itself is improving. The prognosis isn't good.

"Fuck Forever", the still-unreleased Babyshambles song that's become an anthem of sorts (perhaps purely because it has a naughty word in the title), is the one everyone chants for, but when we finally hear it, it's frankly rubbish. Swiping weakly at "Labour and Tory" and whining that "We won't have a say/ Won't have a say/ Oh they'll have a way/ They'll find a way to make you pay". This is doggerel.We're losing a poet and gaining a cartoon character.

After about five songs, the ambulance-chasers get what they came for. Accidentally-on-purpose, Doherty's flailing limbs disconnect Patrick Walden's guitar lead. Walden gives Doherty a kick up the bracket, and Doherty spins round and gives him a girly slap. The ruck is a somewhat pathetic one (Doherty is so weedy that he later loses a tussle with his own mic stand), and within seconds - a little too swiftly for credibility - bouncers rush in to separate the pair. It's transparently choreographed, pure pantomime, Indie WWF Wrestling. The tabloid hacks can go home now.

The house lights come up, but nobody believes the band have gone for good. And 10 minutes later, they're back on, Doherty affectionately gives Walden a telltale ruffle of the hair. Maybe Babyshambles do rehearse some things, after all.

There's another scene of crush barrier chaos this week, in the most unexpected of places. REM are in town playing what is, for them, an intimate gig.

Perhaps you, like me, had REM fans down as mellow, bookish, sedate types, but the mêlée at the front of the Apollo is enough to cause Peter Buck to stop and wander over with concern, and Michael Stipe, wielding a megaphone and with lurid turquoise warpaint smeared across his eyes, to raise a quizzical brow.

The dilettantes up on the balcony may only be here for "Everybody Hurts", "Losing My Religion" and "Man on the Moon" (Stipe, perhaps mocking the hits-only fans, points to the words "yeah yeah yeah yeah" on a painted sign, to help them sing along), but the nutters on ground level are being treated to a markedly fan-friendly set including songs which haven't been played for almost 20 years, and at least one song from every album except Fables of the Reconstruction and Murmurs.

Perhaps you, like me, also had REM down as a dull, worthy experience, but there's little of that tonight (and seeing gentlemen with their aging bones managing a forward roll deserves applause in itself). Instead, they're having fun with their own self-important mythology, and for a man who can often come across as pompous, Stipe is engagingly self-deprecating, admitting to hitting grievously bum notes on "Imitation of Life" at a previous London gig, and that "Swan Swan H" (one of the aforementioned rarities) is the most pretentious song title he's ever written. Just as well. If he hadn't said it, I would.

s.price@independent.co.uk