If you stay all the way through the final credits of the movie "The Aviator" there's a song by Leadbelly about Howard Hughes and his record-setting flight around the world. I never knew such a song existed but that's definitely Leadbelly singing. He and Alan Lomax are credited as the writers. (I stay for credits.)
Also, playing nightclub singers (and actually singing) in the movie are three Wainwrights: Loudon, Rufus and Martha.
This is not a recommendatation for the movie. I think I'll buy the CD, though.