re.Robert Johnson-RJ went to his step-sisters house in upstate New York, where, with her help (she was an English teacher, and semi-pro pianist) he perfected his Delta Blues delivery and lyrics. He likely studied commonly available records of the time, as well as detailed notes, made while studying with Son House, Honeyboy Edwards, etc. As far as the "selling his soul" deal, well, sure he did; along with the majority of other popular secular musicians of our time. RJ's lyrics are just anther twist on humankind's narcotic mythology/symbolisms that have been around for thousands of years-now part of the whole psyche/society of the modern world. If you don't know how all-pervasive this is, ask someone who knows...