Down from the Mountain and O Brother soundtracks are great, but one that I like even more is "Songcatcher". I don't know if there's been a previous discussion of this, I suspect so, but it is FANTASTIC. The movie is amazing, too. Also featuring Gillian Welch, and Emmylou Harris, as well as Emmy Rossum, Rosanne Cash, Pat Carrol, and Hazel Dickens (+many more). Not to be missed!