Broken Social Scene - London Astoria

Perhaps South Park's creators were onto something when they laid the blame for the pollution of mainstream ideals and the corruption of all that's 'good and American' at the feet of a pair of psychedelically odd-looking, feet tapping Canadians. Because just like the cartoons Terence & Philip, Broken Social Scene are ripping up today's social norms, giving wide-eyed kids food for thought, and regurgitating the rule book side of stage. Ok, they don't sing about 'uncle fucking', but their composition of band members is almost as incestuous, and because this is indie rock we're talking about, they're rapidly becoming cooler than a remote controlled Arctic Monkey with changeable limbs.

Emerging onto no particular 'scene' of any description with their 2003 debut album 'You Forgot It In People', BSS have developed into more of a loose jamming supergroup than a band as such, in the process making Mystery Jets sound more 'frog' than 'prog' and leaving The Dandy Warhols looking more polished than a Westlife key change. Made up by members of The Dears, Stars, Do Make Say Think, Metric, Feist and various other mates from the Canadian label Arts & Craft, their rasion d'etre has become almost as muddled and indefinable as their ever-tradeable number, managing to puzzle, bemuse, and simultaneously delight audiences and critics alike with their quirky cauldron of avant-art pop that has put a massive finger up to the traditional cross-border cat calling from their southern yankie neighbours who've all been smugly whistling Bryan Adams at them for the last 15 years. The band have even got a song called 'Canada Vs America'.

Shunning a support band in favour of letting loose on their own for two solid hours, BSS use every inch of space on London's Astoria stage, emerging like extras from a tree-logging soap opera based on the edges of Lake Ontario, with a selection of guitars (six of them), trumpets, violins, horns and two drummers. To say they blend perfectly would be to outwardly lie - and also to totally miss the point - for while it can often be difficult to hear the trees from the wood in the thick mist of their baggy, off kilter drawl, BSS splice together a hypnotic genre-bouncing soundtrack that flits from swirling cascades of power rock into messy, multi-instrumental psychedelic jams that just beg for spliffs to be brought round freely on trays.

With the band's earlier tracks reminiscent of Dinosaur Jr's ragged sound-squalls, full of meandering guitar solos and shrieking riffs, their growth in number over the years has unquestionably enlarged their sound too - although not enough to exclude them as one of Dinosaur Jr's guests at the forthcoming All Tomorrow's Parties weekender. So where the Sonic Youth bubbling 'Cause = Time' brims with teenage bedroom bravado, recent single '7/4 Shoreline' is more a collective coming of age with its scuzzy but soaring anthemic chorus. With two drummers competing for tonight's tag of 'most mangled/chopped up beat pattern' the two-hour journey often rests with theirs, and at points goes off on unwelcome tangents as euphoric, tangled maelstroms are temporarily replaced with experimental, broken-beat dance tracks which seem even more out of place than they do on the new eponymously titled album. But fortunately it's a small price to pay. And ultimately both brave and interesting.

Inevitable comparisons have been made with fellow canook beat lovers, Arcade Fire, although such parallels are both lazy and misjudged. For while both bands share a similar ambition in engaging those usually neglected corners of the soul, BSS are determined to corrupt rather than cleanse. They may be riding slightly on the success of Arcade Fire last year, but don't forget, they got here first. And while the latest outpourings from their US neighbours (Clap Your Hands Say Yeah, Spinto Band) are all about sculpted elegance, Broken Social Scene are happy to wade in their own murky marshland. Blame Canada? Fuck yeah.