Aelric my second to favorite song from this soundtrack, next only to that soulful moaning by the grave diggers.
BHWW The vocals are courtesy of bluegrass legend Ralph Stanley, who became a name with his late brother Carter back in the 40's and 50's. When you hear the traditional 'Angel Band' over the closing credits of O Brother that's the Stanley Brothers.
I'm a fan, needless to say. I read one person describe his voice as having a "high lonesome" sound to it. I think that's pretty apt. His duet albums with various other artists were also great as well.
takewithfood I love this movie, but can't imagine sitting through it without the music. What a great recording.