Founded roughly ten years before the ratification of the US constitution, the town of Nashville, Tennessee, has become synonymous with some of the most synthetic music on the planet. Take a stroll through Music City today, and trashy songs will bounce off your ears like beer cans tossed from a redneck's truck.
The music known as "corporate country", with its distant roots in Afri- can blues, European folk and Native American soundscapes, is probably the most closely associated with white, mainstream America. And it has chased off the soul of the original pioneer sound, just as surely as the star-shaped Fort Nashborough displaced the Woodland Cherokees, and the Mississippi Creeks and Chickasaws.
But for signs of life in the polluted mainstream, head to the Barbican's "Way Beyond Nashville" festival. According to its neon posters, this is a celebration of the "intrinsically American yet powerfully universal twisted heart of country music", more commonly known as "alternative" or "alt" country.
"Altcountry" is a broad-brimmed stetson of a title, casting its cool shade over a wide range of styles from the blues-punkish thrash of the White Stripes, through the jazzier lilt of Lambchop, the Tijuana twang of Calexico, the Kylie samplings of Howe Gelb and the fiddle-stompings of The Pinetops, to the more traditional banjo-scuttled blue-grass of old hands such as Ralph Stanley and Chip Taylor. Its exponents - young and old, rich and poor, rural and urban - come from across America.
These disparate acts are united by an uncommercial honesty that has earned them a fan base on this side of the Atlantic. Indeed, America's edgier music now has to travel to Europe for "validation" before it is accepted back home. This pattern was established in November 2001, when the Barbican held its first "Beyond Nash-ville" in the aftermath of 9/11. Hosted by the Arizonan wildcard Howe Gelb, a procession of altcountry stars took solo turns at the mike before melding into a one-night-only supergroup. Unlike most pop stars, these performers were modest, humorous and generous with each other. When Dorset's own rock chick, P J Harvey emerged in a cowboy hat for an explosive take on the 1970s punk screecher "Johnny Hit and Run Paulene", the polite crowd went wild. Time Out proclaimed it "gig of the year".
Since then, many altcountry musicians have risked commercial ruin at home and gained credibility abroad by speaking out against the Bush administration. The Dixie Chicks might have sung the American national anthem at the Super Bowl in January this year, but in March the lead singer, Natalie Maines, told an audience in London: "We're ashamed that the president of the United States is from Texas." In the US, they were dubbed "Saddam's Angels" and their CDs were set on fire; in the UK, their sales rose overnight.
The high priestess of country, Emmy-lou Harris, has also joined the anti-war protesters, along with Lucinda Williams and Johnny Cash's daughter, Roseanne. Chip Taylor's last album painted an apocalyptic vision of a future America, where children in gas masks on grey front lawns ask: "Mommy and Daddy, did we vote for them?" This is not to say that all altcountry artists are anti-war, anti-capitalist, or even particularly political. But they are freethinkers. From the Somerset peasants who railed against the lord of the manor to Woody Guthrie's 1930s Depression blues and contemporary bands such as Lambchop, folk music has always had protest at its heart.
This year's "Way Beyond Nashville" festival has extended beyond the bunker-grey walls of the Barbican Centre to reach several other London venues. Highlights will include the craggy-voiced John Hiatt, smoky Emmylou Harris and a delayed appearance by 75-year-old Ralph Stanley. The wonderfully arch Handsome Family will be appearing in Shepherd's Bush to perform songs from their new album, Singing Bones.
One song is a dark parable about a nameless, ordinary Ohio man who discovers "a deep dark hole" behind his barn. His wife lowers him down it in a rusty, clawfoot tub. When the rope runs out, he switches his knife across the fibres and falls into the void. "But until I hit the bottom," he insists, "I won't believe it's bottomless." From the voices that echo through "Way Beyond Nashville", you can hear that somewhere the penny has finally dropped.
"Way Beyond Nashville" is at the Barbican Centre, London EC1 (020 7638 5403) until 20 November. A festival compilation album will be released by Casual Records