So, I recently stumbled onto an alternate version of this song from the 'O Brother, Where Art Thou?' soundtrack. It's got a whole different feel to it with just the acoustic guitar under the vocals. Pretty funky.
Apparently, Clooney was so bad at lip-synching that the set guys created the worlds biggest pop filter (circular thing between your mouth and the mic) to cover his face while he faked the singing when they were in the 'studio' scene. Also, the guys doing the background vocals at the end of each verse managed to sing 3 part harmony even though there were only two of them!! Ha!!!