The Klaxons: Siren sounds

When they started out as a joke band in 2005, the Klaxons had no inkling that in less than two years they would have beaten off the Arctic Monkeys and Amy Winehouse to win the Mercury prize, the most coveted award in British music, for their album Myths of the Near Future.

On Tuesday evening, there were gasps of surprise from an audience confidently expecting a victory for Amy Winehouse, who had delivered a stunning performance of "Love is a Losing Game". But the south London four-piece, ecstatic and astonished though they were, had little doubt about why they had won.

"I just think that we're making forward music and the Mercury – as far as I know – has always been about making forward music," said the singer and bassist Jamie Reynolds.

"Forward music" is definitely what the twentysomething Klaxons are about. Since they released their debut single "Gravity's Rainbow" in March last year on Angular Records, they have become pioneers of the "nu rave" music scene. It's a term that Reynolds himself coined, in jest, to describe the way his band recalls the UK's dance era of the early 1990s. In spite of his insistence that the term was a joke, the NME jumped on the bandwagon. It has since taken on all the weight and significance of a British scene that includes the electro-rock band New Young Pony Club (also up for the Mercury for their debut album Fantastic Playroom), Hadouken! and Shitdisco.

The original trio (drummer Steffan Halperin officially joined the band after Myths) are hip and colourfully clothed. The guitarist and backing vocalist Simon Taylor-Davis took a fine art course at Nottingham Trent University and, in another nod to the band's indie-pop cred, is going out with Lovefoxxx, the lead singer of the equally exciting and popular Brazilian band CSS. The singer and keyboardist James Righton was persuaded by Taylor-Davis, a school friend, to indulge in a long gap year after his history degree and join the Klaxons in late 2005, and the band were formed.

The Mercury win was based on their debut album, but it is their live shows that are their top trump, their energy injecting party atmosphere into any venue. Their predominantly teenage fans are known to turn up at their gigs in neon-bright outfits, clutching glowsticks.

The Mercury judges praised Myths of the Near Future, which reached No 2 in the charts after its January 2007 release. "Rock meets pop meets dance," they said, "the Klaxons take us on an ecstatic musical adventure."

The band take rave from the Nineties, draw on the guitar dance music genre encapsulated by The Rapture's "House of the Jealous Lovers" and combine electro with guitars – and make it all their own. It's pop, it's melodic, it's escapist and it's exciting.

They booked their first gig before they had released any songs, but they now boast four Top 40 singles: "Gravity's Rainbow"; "Magick"; their synth-punk cover version of the 1995 house track "Not Over Yet"; and the Top 10 single "Golden Skans". The B-side of their first single was a cover of Kicks Like a Mule's "The Bouncer".

This year, the surge of crowds cramming into tents to hear the Klaxons at festivals showed that their popularity had been underestimated. On top of that, they reference the writing of Richard Brautigan, Thomas Pynchon, JG Ballard and Alfred Jarry, adding a certain intellectual gloss. The word "klaxon" derives from the Greek verb "klaxo", meaning "to shriek", and their album is named after a short-story collection by Ballard.

Their catchy, addictive up-tempo track "Golden Skans", which they played at the Mercury ceremony showcase, begins with the chord change to Baby D's "Let Me Be Your Fantasy", while its lyrics refer to Ballard. It seems an incongruous mix, but it works.

What the Klaxons represent is the now, the urgent presence of youth and the elation of carefree hedonism that goes with it.

The Mercury Prize had a reputation for putting an end to its winner's musical careers until the Arctic Monkeys managed to secure a second nomination after going from strength to strength. This year's winner is certainly a band responsible for pushing the boundaries of indie rock and guitar pop, but whether they are a career band is another matter.

The Klaxons are said to be working on a second album, and are going back into the studio in January. But when a band is feted for their originality and for being so much of the moment, can a second album ever match the first? By the time it is released, will we still care? Or will we have moved on to the next big thing?