https://www.texasmonthly.com/arts-entertainment/mack-mccormick-quest-to-find-real-robert-johnson/
Not that I was going to read it anyway (because at this point I don't/can't care anymore), but this article is a fascinating look at the author and how some mythologies are created, not always benevolently.
It might be telling that McCormick named his by all accounts staggering archive "The Monster"