I bought a Washington Phillips CD about two years ago but didn't get around to listening to it till this week. Amazing.
He self accompanies on a.... well that is part of the mystery. No one is 100% sure what he is playing. It's some sort of pair of modified zithers or something along those lines. Here's a link about the man and some background info:
http://www.fretlesszithers.com/wp.htmlAlso has some music clips and a link to Yazoo's reissue of his work.
When I listen to work like this I am so grateful it has been made available but at the same time I have to wonder what was out there that was never recorded at all?