HERE is a little poop on the movie. I checked Blockbuster and they list it, but say it's not available for rent or purchase. I got it from the Seattle Public Library, so if you have a fairly large library nearby, that may be a place to check.
I took it for what it was, enjoyed it, and thought it was actually a pretty good movie. Hardly accurate, but then when I was a kid, I saw a lot of movies like A Song to Remember, which was supposedly a biopic about Chopin escaping from Poland and giving concerts in Paris to raise money to drive the Russians out, and Song of Sheherazade, presumably about Rimksy-Korsakov's adventures when he was a cadet in the Russian navy, courting a Spanish beauty in Morocco, and trying to write music at the same time. They were accurate only in the broadest sense—that these were real people, the story followed the general curve of their lives, and some of what they depicted was accurate—but with a lot of Hollywood goat-feathers thrown in for the sake of sheer story-telling.
Leadbelly is much the same, but what makes all three of these movies good is that they are packed wall-to-wall with the music of their protagonists.