Robert Johnson, while probably the most influential of all blues guitarists, is also one of the most obscure. Recognized as an influence on musicians like Eric Clapton and the Rolling Stones, Johnson was poisoned by a jealous husband in 1938--at the age of twenty-seven. This untimely death, his supposed bargain with the devil that enabled him to play guitar, and the ferocity and tormented originality of his work have given rise to a legend that has...