Relaxed Muscle, Victory Services Club, London

It's Jarvis, but not as we know him

Of late, you might have expected British pop's king of corduroy and caustic observations, Jarvis Cocker, to have kept his pointy-fingered lewdery out of the press. Last year, at a dazzling gig in Rotherham, Cocker put Pulp on ice for a year - possibly permanently - with the declaration: "We may meet again, who knows?" Then, Pulp's Hits album bombed big time, the band left Island Records, and it was au revoir Cocker, as he moved to France to embrace marriage and fatherhood in privacy.

Well, that lasted. A few months back, Cocker cropped up again with a string of EPs, gigs and news stories on the back of a wickedly named new band, Relaxed Muscle. Sure, he was operating under the guise of "Darren Spooner", alcoholic Doncastrian club singer and petty thief, and sporting ghoul's make-up, skeleton outfit and straggly hair that made him look like a sickly Alice Cooper. But it was him all right, with occasional Pulp guitarist-cum-solo crooner Richard Hawley (aka "Wayne Marsden"), and Jamie Buckle, from the Fat Truckers, in tow.

It's not Cocker's first wily prank, of course. He achieved tabloid notoriety - and was taken to the hearts of a good proportion of the nation - after baiting Michael Jackson at the 1996 Brit awards. He's played with Pulp alongside a lookalike, singing "The Fear". It's not the first outing for Muscle music, either: "The Heavy" and "Rod of Iron" were bashed out when Cocker and Hawley supported Lee Hazlewood at London's Royal Festival Hall last year, accompanied by some cod-karate silliness from the singer.

But Relaxed Muscle have evolved into, at least, a temporarily going concern. They've been flexing their pecs a lot lately, playing low-key gigs such as the plush Victory Services Club. (The show marked the opening night for the Frieze Art Fair, for which the music programme was co-curated by the Pulp guitarist Steve Mackey.) As Spooner, Cocker hides his old charm behind a distorted voice and unreconstructed, unbalanced between-song rants - against, say, "fookin' fat bastards" and a too-loud guitarist. "Call yourself a fookin' professional?" he howls.

Musically, the opening "Muscle Music" sets the tone. A punk-a-billy romp that could be a variety club-style, bad cover version of "Ant Music", it's followed by a mess of loud, fuzzy electronics mixed with grizzled guitars and glam-industrial beats, somewhere between T-Rex, Suicide, Cabaret Voltaire and electroclash buffoons Fischerspooner. (Presumably, Darren is Fischer's northern brother.)

It is the "sound of young Doncaster", according to Spooner, but is it the sound of Cocker? Well, just. His satires of lairy lads on the lash in Pulp songs such as "Joyriders" linger in "Battered", which wades into the thick of a weekend battering. Where Pulp's "A Little Soul" was a moving ode to a deserting father, Muscle's "Mary" - tonight's blackly funny encore - is its grim underbelly, in which a wayward old man warns his ex-wife that their kids are on drugs. ("OK, I haven't kept up with the payments..." he ventures, weakly.) And if Pulp could be dirty devils, Spooner gives Cocker carte blanche to fly off the leash on spooning innuendo. "My beast it is the best," he pants on "Beastmaster": "Wanna put me to the test?/ You're gonna need a week of rest." Honestly, boys.

It's a lark, then: hardcore, maybe, but not so much, "This is Hardcore", as, "This is the Electroclash Spinal Tap". And if Blur's Damon Albarn can have a cartoon second band in Gorillaz, and The Darkness can strut a thin line between deeply daft and "listenable" (to some people, at least), why can't Jarvis Cocker? It's even fun, for 50 minutes. But it's ultimately too silly to be potently satirical, or particularly good. You have to hope that, as Pulp's year of rest comes to an end, Cocker has something more up his flapping sleeve.