There was legendariness aplenty at the opening night of the Barbican's Further Beyond Nashville season. Los Lobos have been patiently refining their mix of blues, boogie and barrio dance music for 25 years - and it was more than 30 years ago that Butch Hancock, Joe Ely and Jimmie Dale Gilmore put together The Flatlanders in their hometown of Lubbock, Texas.

The Texans went first. Impossibly relaxed and hugely entertaining, they breezed through their set with comic nonchalance, the narratives in the songs spilling over into improbable yarns and tall stories from all three frontmen. Each has a bulky personal back catalogue - Hancock alone has written enough songs to fill the Channel tunnel - but the collective nature of the band lets them pool their talents without swamping their individual strengths.

Thus Gilmore's high and lonesome tenor was discreetly highlighted, while Ely played the earthy gunslinger and Hancock took on the role of bard-in-chief. How appropriate that Butch should sing You Make It Look Easy, since they did, from the ludicrous shaggy-dog story of The West Texas Waltz to the fantastic fable of Ride to Heaven ("My name is Jesus Christ, I need to see my dad"). Bobby Gjersoe's superb electric guitar - galloping from western swing to honky-tonk and bluegrass - was the icing on the cake.

After the break, Los Lobos loped onstage exuding deadpan, low-rider cool, and eased into the eerie groove of Kiko. The antidote to showbiz, Los Lobos just get up and play and hope you'll jump aboard.

You hear the best of Los Lobos in their passages of collective improvisation. As David Hidalgo, Cesar Rosas and Louie Perez deftly pass the ball around on guitars, the drums and percussion rearrange the superstructure and take the beat for a walk, usually somewhere in the direction of Latin America.

The longer they play, the more layers emerge in their music, like the shadowy balladry of Angels With Dirty Faces or the jolting beat of One Time One Night. There was even an episode of west coast cool jazz, with Steve Berlin's barking baritone sax summoning the spirit of Gerry Mulligan.

In memory of John Entwistle, they encored with The Who's My Generation - more evidence of the infinite expandability of Lobos-world.

· Further Beyond Nashville is at the Barbican until December 11. Details: 020-7638 4141.