Elijah, at

http://www.elijahwald.com/rjohnson.html

your website still says

"WHAT IS BLUES? [...] first it was a black pop style[...] it retroactively became a folk style[...]"

I wonder if you'd consider changing that since, as discussed above in this thread and by you and me several times over more than a decade, you have zero credible evidence supporting the idea that pop musicians (black or otherwise) helped invent blues music. (See above for the issue that 1905 was different from 1910.)