Vampire Weekend, Electric Ballroom, London

When was the last time a lead singer took to the stage in a yellow V-necked sweater with sleeves pushed up to the elbows? This was Ezra Koenig, Columbia University graduate and 23-year-old Vampire Weekend frontman, and he looked as though he'd just stepped out of a tutorial and was about to settle down on the faculty lawn to do some serious background reading.

If preppy is the new cool then Koenig and his three-band mates – Columbia alumni all – have it in abundance. But there is so much more to them than that, as the dazzling show with which they closed their biggest UK tour to date demonstrated.

The buzz has been building around Vampire Weekend for a while. Their 2007 debut album – self-titled – was strikingly original, with its exuberant blend of African guitar sounds and east-coast new wave. Lyrics that offered a witty if sometimes baffling take on the lives and concerns of privileged New Englanders, not to mention tackling such subjects as punctuation and architecture, deepened their intellectual appeal even as the band ran the risk of being just a bit too clever by half.

The album has now sold more than 300,000 copies, and after appearing on Jonathan Ross's TV show last week, Vampire Weekend seemed to have outgrown venues like the Electric Ballroom as a packed crowd waited – and waited – for them to come on.

Fashionably late has gone so out of fashion that one began to wonder if this was just another game from this most playful of bands, but whatever caused a scheduled 9.15pm start to push back to 10 o'clock, it did the trick. Rare is a London audience as animated as this one was from the moment Koenig kicked off with "Mansard Roof" and an explosion of musical colour filled the air. Energy levels were maintained with "Campus", "Cape Cod Kwassa Kwassa" and "M79" and never really let up.

Graceland-era Paul Simon is often cited among Vampire Weekend's musical antecedents, and it's a valid comparison, but the vibrancy of their music, and the way it played around with catchy rhythms, somehow connected it to the even deeper American traditions of Copland and Bernstein. Their technique was disciplined but their spirit ran free, and the combination was winning.

While great intros are something that every band strives for, Vampire Weekend have a genius for great endings, achieving maximum impact with the startling climax to the hectic "A-Punk". Departures into new material were not so successful, but Koenig brought it all back together with classics "Oxford Comma" and, as an encore, "Walcott". These fellows really are in an Ivy League of their own.