Watch the My Heart is Kind online guitar lesson by Jeff McErlain from Essentials: Solo Electric Blues
There is a supernatural side to the Robert Johnson legend that says he went to the crossroads and sold his soul to the devil in return for his musical ability. This is actually a recurring story throughout musicians, one that often helped their career. The virtuoso violinist Niccolo Paganini used this same story to boost his reputation. It's unclear if Johnson took advantage of the story but I'm sure it didn't hurt his career. With songs like "Hellhounds on My Trail" we can see how the legend grew. His life was cut short by what what was believed to be a poisoning by a jealous husband. He was only 27.