oh brother where art thou/nickel creek

A while ago this group nickel creek was performing at a show that aired on PBS that was celebrating the movie "oh brother where art thou" and I can't remember the name of the song they played. It was all acoustic and it was beautiful. HELP!

Hello,

maybe it was: "I'll fly away". Here's a link to the original movie-song: http://www.youtube.com/watch?v=sdRdqp4N3Jw , and here is a link to nickel creed, performing the song, but the quality is unfortunatly not the best: http://www.youtube.com/watch?v=5Wwo3Is0lt4 .

Greetings,
Alahn