As expected, Joel and Ethan Coen's O Brother, Where Art Thou? brought little but joy into the world. The film was as dense and funny as any they've ever made, but unlike past efforts, it created a miniature cottage industry with its soundtrack, a collection of traditional and traditional-ish American roots music that's been a fixture on the charts since its release. Whether the O Brother soundtrack will have far-reaching effects, helping reconnect listeners to a musical heritage, or simply become the trendy niche music of the moment (Chant, anyone?) remains to be seen. But Down From The Mountain can't hurt its case. Directed by D.A. Pennebaker, Chris Hegedus, and Nick Doob, Down covers a concert of selections from the O Brother soundtrack, featuring performances by Ralph Stanley, Chris Thomas King, The Whites, Emmylou Harris, Gillian Welch, Alison Krauss, and others. As a film, not much more could, or need, be said of it. Pennebaker and frequent collaborator Hegedus (The War Room, Startup.com), generally excel at behind-the-scenes material, but they limit themselves here; their conversations with the artists, though frequently entertaining, rarely reveal much. Reluctant to dress up for the occasion, Welch quickly changes her mind when reminded that Stanley will be wearing his finest suit; Harris interrupts a stirring backstage performance mid-song to check on a beeping gizmo that keeps track of baseball scores. Both scenes provide fleeting but telling insights into the music and the artists behind it, but the film seldom digs deeper. Instead, it mostly focuses on the actual concert, which was wryly emceed by the late John Hartford. The music, as might be expected, takes care of the rest. That's especially fortunate, given that visually, Down From The Mountain is pretty undistinguished. Its use of digital video—in some cases by cameras seemingly equipped with an "uglify" filter—is a fairly dispiriting case of current technology being used in a way that, to paraphrase a line from the Coens' film, is pretty far from old-timey. But, given this music, Down works anyway. It would be hard for it to fail.