Capitalizing on the surprise success of the O Brother, Where Art Thou? soundtrack, the contributing artists -- including Alison Krauss and Union Station (featuring Dan Tyminski, lead vocalist of the Soggy Bottom Boys), the Cox Family, Gillian Welch, John Hartford, Emmylou Harris and Nashville gospel institution the Fairfield Four -- staged a performance of pre-country music at the Ryman Auditorium. Soundtrack producer T-Bone Burnett captures the event in the raw, with very much the same field-recording quality that made the O Brother songs seem jarringly different from manufactured country radio fodder. The "hits" Man Of Constant Sorrow and O Death are conspicuously absent (likely, to avoid cutting into the soundtrack's sales), but the power of these performances is undeniable. Gillian Welch plays the Phoenix August 9.