Just before O Brother, Where Art Thou? premiered at Cannes, Pennebaker (Monterey Pop, Don't Look Back) and his crew went to Nashville to film a gala concert featuring the musicians who had played and sung on the Coens' soundtrack. In the event, the film's success spawned a surprise million-selling hit for the accompanying CD, thus helping to broaden the audience for bluegrass, gospel and American traditional music, a process this movie can only continue. Following a modicum of backstage chat as bonhomie and mutual respect flow between the assembled performers, it proceeds as wry MC John Hartford ushers on both those artists you may well have heard of (Emmylou Harris, Gillian Welch, Alison Krauss) and those who were certainly a discovery for this relative newcomer (authentic vocals and pickin' courtesy of The Cox Family and The Whites, timeless gospelling from the Fairfield Four). The keening melodies, lyrics of love, death and hard-earned wisdom, not to mention ace banjo and guitar work, connect back to roots from which blues and soul also sprang.