I love the vocal harmonies on this song (About 1.15):

http://www.youtube.com/watch?v=DbgfQ48hWuY

I thought this was Gospel (or a derivative). I then learned it was based on a slave song, so I've found this album (http://www.amazon.co.uk/Slave-Shout-Songs-Coast-Georgia/dp/B00242VPTC/ref=sr_1_1?s=music&ie=UTF8&qid=1291034209&sr=1-1).

It's not really the same, but im basically looking for very raw old gospel music (I think) with really nice harmonies. Slave music sounds good too.