"B.B." stood for, in some stories, "Beale Street Blues Boy"
I was lucky enough to host Greil Marcus (first name rhymes with "real" not "dial") at Google, and he's written very extensively on the power of the raw blues:
https://www.youtube.com/watch?v=6wBlXAzv0Fg
I'm pretty sure if you woke up Greil in the middle of the night and asked him to speak for two hours about Sun Records, he could do it.