Back in the alt.country

Exactly when it happened, no one can be sure but sometime in the last decade the people who ran Nashville, Music City, USA, gave up the country music ghost. Following the corporate formulae established by fast food outlets and chain stores, the Nashville conveyor belt began pumping out homogenised product, each indistinguishable from the other.

The multi-million-selling success of the permanently stetsoned Garth Brooks was certainly a crucial turning point. A seemingly unending succession of "hat acts" embracing his hi-tech cowboy model followed in Brooks's wake. The maverick spirits and the visionary folk culture that had traditionally enriched country music were swept aside; last orders were called at Ye Olde Honky Tonk. The Stepford Wives style, formation line-dancing colonisation of country was complete.

But significant elements in the country diaspora had long ceased to rely on Nashville central for stimulus or patronage. These days, country's cousins and offspring are as likely to be found working on a computer program in the Arizona desert or in a Chicago tenement block as they are on Nashville's Music Row or at the Opryland Complex. From Howe Gelb's sand-blasted, Mariachi-inflected reveries to the Handsome Family's melange of urban folk reportage and ancient death balladry to Jim White's Florida-based swampland gothic, there has been a reawakening to the variety and possibilities left in the margins as the mainstream focus has narrowed.

Next month, London's Barbican Centre presents Beyond Nashville: the Twisted Heart of Country Music, a season that is dedicated to alt.country, a term coined to label those performers who don't fit into the heavily sponsored, innately conservative US radio formats.

"Its something that's been in the air for a few years," says Miles Evans of the Barbican. "With acts such as Shania Twain and Garth Brooks, it's obvious that Nashville's major labels have become part of the pop industry. But country is always renewing itself, and currently it's more alive and more interesting than ever."

The Beyond Nashville season includes performers from across the US (Evan Dando, Mark Sparklehorse Linkous, Steve Earle) and beyond (Bap Kennedy from Belfast, Canadians Oh Susanna, and the London-based Menlo Park). The factor that unifies these diverse characters, who have mostly thrived on independent labels, is a fascination with country's tangled roots.

Proof that the renewed interest in musical roots wasn't confined to a few left-field musicians came with the unexpected success of the soundtrack for the Depression-era musical feature film O Brother, Where Art Thou?. Put together by Joel and Ethan Coen with the alt.country pioneer T Bone Burnett, it combined archival recordings with new tracks by Gillian Welch and others that were recorded on antiquated equipment.

The album's success highlighted just how detached the mainstream industry had become from its musical past, when radio programmers labelled the music "poison" and refused to include it on their playlists. It has been suggested that one reason programmers balked at the soundtrack was because of its inclusion of black gospel singers alongside old timey and bluegrass performers. Blues and gospel traditions inspired country giants from Hank Williams to Johnny Cash, but mainstream country music remains racially segregated.

The influence of black culture, acknowledged by the inclusion of the gospel legends the Blind Boys of Alabama at the Barbican season, is just one element that feeds the alt.country masses. Lambchop's Kurt Wagner draws inspiration from contemporary gospel and the Seventies legend Curtis Mayfield; Jim White cites Tom Waits' Swordfishtrombones as the spur for his brand of gothic bible-belt Americana. John Convertino's Calexico filter the jazz influence of western swing in a swirl of western soundtracks and Latin flavours, while Alejandro Escovedo (sadly absent from the season) invests his Tex Mex heritage with country and classical shadings.

It's all a long way from Opryland but, as Miles Evans insists, outside influences are consistent with country's development. It was Bob Dylan's appearance on The Grand Ole Opry with Johnny Cash that triggered the Seventies country rock movement. Ethan and Joel Coen are hardly good ole boys, but the genuine love for music expressed in O Brother is a reminder that outsiders often have the sharpest perspective on the music that made Nashville famous. Indeed, it was only after returning to Nashville from Chicago that Wagner formed Lambchop, who over the past decade have represented just one musical community thriving under the nose of the advertising-led big companies.

"It's a pretty jaded industry place," says Wagner of his hometown. "It's what I imagine Hollywood is like, where a lot of people don't buy music or go to shows because it's all strictly business. But on every Lambchop record there's a dedication to the Country Music Hall of Fame. It represents a lot of what's good about the city's musical heritage and there's still so much there to be discovered, in spite of the record companies and radio programmers."

Beyond Nashville is at the Barbican Centre, London EC2 (020-7638 8891) from 2 Nov