David Honeyboy Edwards died at the age of 96. He was the last living link to the original generation of Delta (as in Mississippi Delta) Blues Musicians, including Robert Johnson.  These musicians are original “source” for much of the blues, soul and rock and roll of the 20th Century.  I thought it was quite interesting that he actually played himself in the movie “Walk Hard: the Dewey Cox Story.”  You can read the article here. Edwards performed with Robert Johnson, acknowledged as a foundational early influence for Rock and Roll (he was inducted into the Rock and Roll Hall of fame at their very first induction ceremony.) This piece is in what is call a 12-bar Blues pattern, a formula that was the basis for hundreds if not thousands of songs.

I also found some video:

http://youtu.be/_C8BaalxCjg

Here is the Cream version:

http://youtu.be/ejPi8D8LFnI