First of all Harpgirl. What Leadbelly is doing with his feet is what is known in classical music as "three against two". That is he is tapping one foot in triple rythm 3/3 while he taps the other foot in cut time 2/2.

There were some amateur films made of Leadbelly singing. Apparently they were done with a non-sound camera and the was recorded as he did it. Or else he recorded the songs first and then mimed them for the film. At any rate Pete Seeger took the trouble to synchronize the two. There was also a newsreal of a very young Leadbelly taken during his wedding. All of these are on a Grossman video. I don't have it to hand, so I can't give you the title; but it has two volumes and Leadbelly is on vol 2. Both volumes are worth looking at--John Hurt, Son House, and others.

Murray