Placebo, Astoria, London

Male pattern hair loss - it's a rock'n'roll thing, darling

As Howie B once pointed out, angels go bald too. But what about satanic sex pixies? There was much discussion last year – well, in certain circles, anyway – when pictures emerged from a Placebo gig which showed a distinct cat's arse developing at the back of Brian Molko's head.

Comes to us all of course, but one couldn't help wondering why Brian hadn't done anything about it. The usual male responses, with various degrees of dignity – shaving, comb-over, wig – are not the only options for a wealthy pop star, and it was surprising that he hadn't addressed the problem by giving Elton's trichologist a quick tinkle.

Of course, as any follicularly challenged man will tell you, it's a sign of testosterone excess. This is the bald man's wooden-spoon consolation – an assertion of manhood to justify an emasculating, humiliating event. But what if your entire persona is based on the very opposite of manhood? On being, let's face it, a bit of a ladyboy? Before tonight's comeback show, much of the speculation is about Brian's tonsorial situation. The live ads in the papers show him with an alarmingly plasticky, painted-on head of hair – has he done a Numan? The reality is that he's clipped it short, smeared some gel on it, and made the best of things. And in a way, it makes him even more androgynous. He used to look like a pretty girl. Now he's a pretty girl with a bald patch.

Not that the nation of nancy boys and fancy girls care: from the moment they catch a glimpse of the bonsai satyr's torso through his half-undone shirt, the screams rarely subside. They're a peculiar visual spectacle, Placebo. The height differential between the front twosome of Molko and Stefan Olsdal ("Viking" as Molko joshingly calls him later) is even more pronounced than it is between the Manic Street Preachers duo of Bradfield and Wire. It's a freakshow of sorts, but then the audience are, willing or otherwise, freaks themselves, so the mutual love-in is self-perpetuating.

The tribal aspect of Placebo fandom means that they're largely immune to the tides of fashion, never mind the progress of male pattern hair loss, and in many ways, I find myself in agreement with the diehards.

Yes, I can hear your voices: Brian is an irritant (and the fact that it's deliberate doesn't make him any less so). And yes, I can hear the voices in my own head: he's written some songs which make me cringe. Tonight, I hear two of them. "Slave To The Wage", with that couplet "Sick and tired of Maggie's farm/ She's a witch with broken arms", is the kind of lyric you write if you actually spent the Thatcher years in Luxembourgeois luxury. And "Pure Morning", with those awful "need/ weed/ deed" and "breast/ rest" rhymes, still smacks of back-of-an-envelope, half-an-hour-of-studio-time-left desperation.

Then there's his tendency toward obviousness. The way he explains that "This Picture" was inspired by the cigarette-stubbing habits of "James Dean, who if you didn't know, was GAY..." The way he seems a little too pleased with his own naughtiness for mentioning drugs in "Special K". The way it all gets a little too Carry On when he asks "Has anyone got a fag?" (OK, maybe we'll forgive him that one).

And yet, there's something about the texture of Placebo, rather than the text – the interplay of those serrated guitars with Molko's sheepy bleat – which still reels me in. And if you don't find his imagery too hackneyed – the language of blood and roses and death and decadence – he can write with eloquence. During "Without You I'm Nothing", a friend of mine starts sobbing quietly, and rings her ex-girlfriend in Israel.

With the exception of "Lady Of The Flowers", tonight's set neglects the first album almost completely: no "Nancy Boy", no "Bruise Pristine", no "Teenage Angst" (well, not the song, anyway) and, most disappointingly, no "36 Degrees". The new album, Sleeping With Ghosts, has plenty of moments to match, possibly too closely... but tell this crowd that Placebo's lack of progression is a problem and you'll get a slap.

But for me, herein lies Placebo's main problem: their refusal to think outside the straight and narrow lines of alternative rock. The first time I met Brian, or maybe it was the second, we had a good-natured, but impassioned and ultimately intransigent argument over who was better: Euro-house "Dreamer" hitmakers Livin' Joy, or Sonic Youth? (Which dates the conversation with carbon accuracy – can you imagine anyone defending the honour of Sonic Youth nowadays?). In case you hadn't guessed, Brian was battling for SY and I was doing LJ's dirty work.

I still maintain I was right, and from tonight's performance, I can see that Brian hasn't given ground on this one either.

Before the encore, he tells us they've just played BBC2's Re:Covered show on the same bill as Liberty X, who did a Radiohead song, and Elbow, who did a Sabbath one. "Of course," he controversially clarifies, "Liberty X were fucking SHIT, but Elbow were great." What, damning a dance-pop act and bigging up an indie band in a room full of alternative rockers? It's a good job the folks on the balcony are sitting down, or else they might tumble onto our heads in shock.

We're introduced to "new male member" (ho ho) Xavier, a member of Molko's band in Velvet Goldmine, and formerly of RoMo legends Dex Dexter: "He used to be a RoMo, but now he's in Placebo." Xav adds keyboards and haunting hoots to the closing song. It's Pixies' peerless "Where Is My Mind", and it throws projected images of those collapsing tower blocks from the finale of Fight Club onto the screen in your skull. Which is fine, but next time, I wanna hear him try "Dreamer".

s.price@independent.co.uk

Placebo are touring the UK to 23 April. For details, visit www.placeboworld.co.uk or call the hotline on 0115 912 9173