It's a summery Tuesday evening and the crowds on Brick Lane, hipster heartland of the East End of London, are out in search of drink-fuelled fun. Upstairs in a nearby bar, however, a panel of experts is earnestly debating the politics of folk music.
Chris Wood, a musician, argues passionately that folk embodies the history of "ordinary people" and describes it as "our greatest cultural resource". Neil Davenport, a music journalist, disagrees. He suggests that we like folk music "because we find modernity repulsive".
"Rubbish!" shouts the singer Barb Jungr. A well-refreshed audience member makes the helpful point that folk music is all "shite" and points out that "no one's mentioned the Nazis yet".
Nazis excepted, we are here at the invitation of the Institute of Ideas think tank, whose communications director, Shirley Dent, is chairing the discussion. "Something's going on with folk today," she says.
Dent is right. The word "folk" might conjure up an unfashionable stereotype of beards, sandals and folderol lyrics, but its influence extends, tendril-like, into every corner of our musical culture.
Recent years have seen a wave of folk-influenced pop acts including the American harpist-singer Joanna Newsom and the British band Tunng; this year's Proms boasted a Folk Day; and in the Imagined Village project, a collective of musicians, including Chris Wood, Billy Bragg, Benjamin Zephaniah and Eliza Carthy, mixed traditional English song with the music of contemporary, multi-ethnic Britain in an attempt to promote a "progressive" national identity.
Not everyone is happy with the resurgence of folk music. "Why are we trying to revitalise politics today from the struggles of the past?" asks Dent. Wood counters that folk songs tell history from the point of view of ordinary people. Davenport weighs in with the claim that folk "romanticises a peasant ideology" and that its early proponents were driven by racist impulses.
It's true that folk has been intertwined with some decidedly dubious ideas about culture and authenticity. John Lomax, the early-20th-century American musicologist, decided that the most authentic black American folk songs were those that harked "back to Africa" and sounded like "the tom-toms of savage blacks". And Cecil Sharp, the great English collector, wanted to identify an ethnically pure British culture, based on a romanticised ideal of the working class. Such views helped shape the folk and blues that we know today.
So does the proliferation of folky stylings currently doing the rounds indicate a widespread hatred of modern life and a desire to return to some imagined pastoral idyll? Actually, no. Like any other genre, folk music is too nebulous to have a single political meaning imposed on it. Old melodies and instruments provide a palette which, when used well, allows musicians to innovate. (I'd defy anyone, for example, to find a recent album more thrillingly modern than Joanna Newsom's Ys.)
A more profound political point, if you're looking for one, is that much of this current innovation has been born from a culture of independent record labels that values creativity and experimentation over the making of a quick buck. It is to this tradition that many of today's folk musicians belong, neither the rarefied world of musicology nor the suspect territory of ethnic nationalism. In the light of this, we should celebrate how they are choosing, in the words of Somerset Maugham (or was it Joanna Newsom?) to let tradition be "a guide and not a jailer".