Like the film it came from, this documentary accompaniment to O Brother, Where Art Thou? is a bit of a hotch-potch. When it's good, it's spine-tingling. When it's not, oh brother, is it dull.
At its core is a concert staged in Nashville to pay tribute to the roots Americana on the soundtrack to the Coen's last movie. It sounds like quite a hoedown, but there's a lot of middling material to wade through, from the dreary backstage footage to David Rawlings' gurning guitar-onanism. On the other hand, the Fairfield Four (all five of them) stomp up an a cappella storm, while riverboat man John Hartford looks every inch the folk devil as he summons up some eerie demons in his fiddle solo.