I forwarded this and the earlier thread to Donald. He has registered here - I hope he decides to enter the discussion. Speaking of discussion - I hope some folks are taking advantage of his website and read the dang books. Rise and Fall should generate some interesting discussions.
IIRC, originally Donald's title for the book was Everybody's Doing It - the Rise and Fall of Popular Music, but the publisher changed it.
Here's a pic of Donald and yours truly in my brother-in-law's back yard. This was a couple of weeks ago.
Blind Willie, etc used the guitar to comment on the words - the white guys used the words to get to the guitar.
It matters who does the directing, if you admire the original art.