Alt-J, Electric Ballroom

It is not exactly Rock 'n' Roll Babylon, that's for sure. When Mercury Prize-winning quartet Alt-J assembled onstage at the Electric Ballroom last night it was more like a group of cool-looking choirboys gathering for practice with the vicar than music's hottest properties playing the final lap-of-honour gig of their current tour. After a modest "thank you" to the audience from guitar-cradling vocalist Joe Newman they were off and running.

This is a venue where I'd previously seen The Clash at full cannonball tilt and Nick Cave in total self-destructive gonzo mode and Alt-J were never going to be able to compete on those terms. Following their Mercury Prize victory for their debut album An Awesome Wave last week the band, who met while studying at Leeds University, said that they were going to celebrate by taking their parents out to dinner. As the old adage goes, they look like a group who are more likely to tidy their hotel room than trash it, although there is a story that synth player Gus Unger-Hamilton and bassist Gwil Sainsbury were fined $100 each for urinating over a hotel balcony during an American jaunt. In mitigation they claim they were not being rebellious, they were desperate and someone was in the lavatory.

There is an intriguing well-honed looseness to their sound

While there were no fireworks during their album-length set, there was much to admire. Like a raft of modern bands from Hot Chip and The xx to Mumford & Sons Alt-J draw inspiration from a wide range of influences. There were hints onstage of everything from electronica, trippy dub and finger-in-your-ear folk to the juddering bhangra beats of their encore, "Taro". It did not all work perfectly. A mash-up of Kylie's "Slow" and Dr Dre's "Still Dre" was a little too reserved, but elsewhere their crisp, confident compositions, topped off by Joe Newman's trademark wobbly warble, were distinctive enough to see why the judges gave them the thumbs up. "Tessellate" may be the oddest title for a love song in years, but boy is it catchy, even if the nerdy lyric "triangles are my favourite shape" makes the band sound like a group of scary geometry fans.

For all their love of long words and language (the name comes from the Apple keys one has to hit to make the Greek letter Delta and a large three-sided flourescent Delta loomed over them onstage) the foursome also know how to put together a tune that is hard to shake off once it lodges in your brain. The rhythms shifted and shimmied and sucked one in like quicksand on their breakthrough track "Breezeblocks", which lyrically has hints of a murder ballad about it, but is apparently about Maurice Sendack, the author of Where The Wild Things Are.

Elsewhere close harmonies and glockenspiels got in on the act. This is not music to bring down governments, but neither is it innately conservative. There is an intriguing well-honed looseness to their sound. Sometimes it feels like the product of an extended jam, sometimes it feels microscopically crafted. Early comparisons with Radiohead are a little specious, but maybe the connection is a shared desire to experiment, upend expectations and push guitar music into places where it does not always want to go or necessarily fit.

Some have suggested that the fact that a band as new as this can win the Mercury Award proves that music is in a trough at the moment. Esteemed music business and publishing veteran David Hepworth recently wrote a blog in which he speculated on who might have been nominated if the Mercury Award had been around in 1971. I don't think An Awesome Wave is quite up there with Bowie's Hunky Dory, Paul McCartney's Ram, Rod Stewart's Every Picture Tells A Story, The Rolling Stones' Sticky Fingers or Led Zeppelin IV, but I'd choose it over Pink Floyd's Meddle any day.

This gig was the last one on the band's current tour. When they return in 2013 the venues are going to be much bigger and would have been even without the Mercury victory. The Electric Ballroom was a special night though. Not just because of the prize but because it was drummer Thom Green's 27th birthday. The occasion was marked by a spontaneous chorus of "Happy Birthday" and a candle-festooned cake. No fireworks then, but there was at least some fire.

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Watch the video for "Breezeblocks"