These days, a breakthrough band needs a story to match their image and their sound. Kings of Leon, four Bible-belt brothers with religious-sounding names like Jared, emerged in 2003 claiming to have been reared in the back of a van by a Pentecostal preacher. It was so impossi ble to verify that they may as well have claimed to have been brought up in a Wellington boot by a swan - but it worked: their debut, Youth and Young Manhood, shifted 500,000 copies. Accordingly, their new album, Aha Shake Heartbreak, comes littered with tales of rock'n'roll excess.

In the flesh, any suspicion tends to melt away as you are confronted with the Kings' charismatic immobility and backwoods haystack hairstyles. Their tall tales are rendered shorter by frontman Caleb Followill's seeming conviction that this venue is a junior school, while his stoned Tennessee drawl is certainly authentic.

Signed during the fuss that was whipped up around the Strokes, the band are similarly indebted to Television, although in mixing the New Yorkers' guitar pyrotechnics with southern boogie, they have found their own sound. Songs from the new album sound slightly darker, but have their trademarks of sweet pop twangs and Caleb Followill's unintelligible lyrics - half mumbled, half spat. He may be claiming to have "tottered around in my high heels", or saying "for sex you was cheap yeah", or something altogether different. Their more obtuse songs sound like tune-ups, but few bands can get an audience to clap along, unprompted, with new material. Of the old, the rollicking exuberance and whipcrack riffs of Molly's Chambers and especially California Waiting are hard to resist.

· At the Forum, London, tonight. Box office: 020-7344 0404. Then touring.