The Sleepy Jackson, Astoria, London

Like the Flaming Lips, whose long-awaited Christmas on Mars project is due some time this year, The Sleepy Jackson's leader, Luke Steele, apparently has ambitions to make a film. As you might expect from the man who made one of 2003's friskiest albums, Lovers, Steele's proposed script is about a man with several personalities tussling for space in his head. It could be fun, if it's as lively as Lovers. But if it does for cinema what Steele's live form does for his music, it'll be the equivalent of Ed Wood's Plan 9 from Outer Space - a film often regarded as one of the worst ever made, and not unreasonably.

Wood's lead, Bela Lugosi, died early on in the shoot for Plan 9, prompting Wood to replace him with someone who looked nothing like the star but who held a coat over his face in an attempt to disguise that fact. For various reasons, more band members have left The Sleepy Jackson over the past few years than Wood lost actors, but the effect is the same: tonight's band make such a mess of Steele's songs that you suspect them of being impostors.

The Flaming Lips comparison isn't irrelevant. Steele's psychedelic pop songs have the stargazing scope and whimsy of the Lips', with no less affectingly plaintive, happy-sad undercurrents about love and hard-won optimism. His live show, then, could be as startlingly effective as the Lips' super-furry pantomime. So, it's a shock to see the diminutive Steele skip on stage in fist-punching mode, cavorting like a rock Prince and flaunting his instrument in a my-guitar-is-my-shield manner, while the leather-waistcoated guitarist rocks the kind of moves normally seen only when Kiss are in town. Granted, no one expects Steele to unleash Lips-style confetti bombs and dancing bunny rabbits. But when the bassist starts shaving the guitarist's hair during an awful mid-set burst of noodling, it's clear that a rethink of stagecraft is needed. ("I'll finish it off later," the guitarist says, pointing to his newly shorn spot, and you think, in your own time, please.)

All the shape-throwing has a knock-on effect on the music. Three songs in, the ELO-meets-Sparklehorse swoon-pop of "Good Dancers" is scuppered by distorted guitars and a fundamentally horrid let's-jam finale, which sees the guitarist waggling his instrument like someone shaking the drops off the end of his you-know-what. The rockier "Vampire Racecourse" is little altered, but as it was one of Lovers' weaker songs anyway, that's no great achievement. Only the George Harrison-esque "Come to This", a superbly sashaying new song, and the fell-off-the-barstool drawl of "Let Your Love Be Love" impress, but as the latter is followed by the scalping stunt, the good work is swiftly undone.

Sure, Steele is an eccentric talent, and you expect his band to be wayward. But tonight was merely banal, the songs suffocated instead of being given space to shine. Steele seems to be suffering from a Ryan Adams complex: the urge to prove that he can rock out, when his material is clearly cut from an altogether subtler cloth. You hope that he'll manage to nail it next time, but it looks set to be a bumpy ride. If that film gets made, approach it with caution.