The Roads Cross At Clarksdale

In OTL, Robert Johnson was arguably the greatest Blues musician and guitarist of all time; as well as the Grandfather of Rock and Roll. His legend is shrouded in stories of crossroads and hellhounds, jealous husbands and faustian deals; and he was murdered at 27.

However, he was unsuccessful in his own lifetime, and it was years before his records were found and he became a Blues-Rock Legend. But what if he never recorded a single track? How would the Global music scene be changed without his influence; and how would that affect the rest of the world?