From Joel & Ethan Coen's "O Brother, Where Art Thou?" came a blockbuster hit single from the soundtrack.
The Soggy Bottom Boys were credited with "I Am A Man of Constant Sorrow", but while stars George Clooney, Tim Blake Nelson, & John Turturro lip-synched in the video, they didn't record the song. Dan Tyminski of Union Station, Allison Krauss' backing band, was the lead vocalist. To his credit, Nelson did record a song on the soundtrack CD, which I'll try to locate at a later time.