Some of you folks know that I'm a fan of early recordings. One of the attractions for me is the combination of music, scholarship and cultural anthropology.
Here's an article (the name just doesn't do it justice IMHO) from the NY Times Magazine that has spurred some amazing threads amongst collectors.
A little warning, this is much longer than your average article but if you're interested in this kind of stuff, the time is well spent.
http://www.nytimes.com/interactive/2014/04/13/magazine/blues.html