Pop Genaside II The Gardens, London

Outside The Gardens - a large Irish dance hall in the heart of downtown London SW6 - a serious traffic jam is in progress, a block of flats is on fire and a large football crowd is about to emerge from Stamford Bridge. But compared to what is going on inside the building, Fulham Broadway is a sea of tranquillity. The meeting of shadowy South London underground dance trio Genaside II with the Prince backing troupe previously known as the New Power Generation (NPG) is part genre-busting coup and part monumental cock-up.

On-stage, beneath two screens playing soothing Japanese Manga cartoons, are four NPG members: the producer Chilli Phats and MC Killerman Archer (aka two thirds of Genaside II - the third third, Kao Bonez, is too shadowy to do anything so rash as show his face on a stage); and the erstwhile Soul II Soul diva, Rose Windross. The music they are struggling to get to grips with comes from Genaside II's extraordinary new album New Life 4 The Hunted (Internal, released 16 September): a fantastically moody and complex record that somehow manages to weld such diverse components as The Red Hot Chili Peppers' "Under the Bridge", Beethoven's Moonlight sonata and legendary pop-up toaster Eek a Mouse's sainted "bong-diddly- bong-bongs" into a coherent and sternly compelling whole.

On the record, "Distant Noises" and "Why You Watching Me" pick up where the most spacious moments of Goldie's Timeless leave off - transporting the listener to a brave but dark new futuristic jazz-world where Sun Ra reads the weather forecast. In person, the drums sound as if they're being played down a rabbit-hole, and the effect of being asked to clap along to these sombre rhapsodies of urban paranoia by a quartet of moonlighting Prince sidemen is akin to being serenaded at a funeral by some kind of ghastly virtual M-People.

One song really works live tonight, though - the spell-bindingly sinister "Waistline Firecracker" (Internal single, out next week). Like Coolio's "Gangsta's Paradise" rewritten for the London borough of Lambeth, this song summons up the most alarming demons of south London street life. And if anyone out there has ever wanted to know what it would sound like to have Sepultura and Shakatak play on the same stage at the same time, Killerman Archer and his friends from the NPG get tantalisingly close to it.

Just as things are really starting to get going, the show comes to an abrupt and hilariously premature end. "Turn the music down, please," insists an anguished Chilli Phats. "Get the DJ to put a record on ... oh fuck it", and then he is gone. Heaven knows what Mark Morrison and Kylie Minogue - lurking as conspicuously as possible just by the back door - make of all this. But it can only be a matter of time before the phrase "There has always been a Genaside II element to our music" becomes quite commonplace.