If you haven’t heard about the blues legend Robert Johnson — who supposedly sold his soul to the devil to master music, and who sang about walking with the devil, being chased by hell hounds, and making a deal with the devil at the crossroads, and who supposedly died at age 26 howling and barking like a mad dog at the moon — then you have now. To say his impact on rock and roll was astronomical would be to put it too weakly.

Robert Johnson has often been held up as one of the most amazing mu...