Robert Johnson (1911-1938)
African-American blues singer, guitarist and songwriter. Born in Hazelhurst, Mississippi, he grew up absorbing the music of Delta bluesmen, first learning the harmonica and then mastering the guitar. He left home in 1930 and traveled the country, playing and singing at parties, juke joints, barrellhouses, and other venues. In San Antonio (1936) and Dallas (1937) he recorded 29 blues songs, but a year later he was poisoned by a jealous husband. Six of Johnson's blues songs mention the devil or some form of the supernatural. Though all that remains of his legendary work are those Texas recordings, Johnson's influence has been a big influence on later blues players and on rock and rollers including Led Zeppelin, Bob Dylan, The Rolling Stones, U2, Jimi Hendrix and Eric Clapton.
It is a popular urban legend that Robert Johnson sold his soul to the devil in exchange for his talent. The Coen Brothers' film, O Brother, Where Art Thou?, explores this concept with a character of Johnson.
It was actually Robert Johnson's friend, Tommy Johnson who made that claim though. See here: http://www.luckymojo.com/crossroads.html
To elaborate on the above link, not only did Robert Johnson never claim to have done the ritual, but the very concept of "selling your soul to the Devil," in the Faustian-bargain sense, is an importation from European folklore: the Robert Johnson story was promulgated by white journalists who a) attached the story to the more famous Robert instead of Tommy, and b) overlaid their own European-American folklore. As the numerous Hoodoo crossroads rituals collected at Lucky Mojo attest, the crossroads spirit in African-American folklore did not behave like the European devil, and never demanded your soul as payment. (However, the ritual performed on Supernatural is significantly different than the folkloric rituals; the ingredients used in the show's version are much more sinister, and presumably would call up something nastier than the Hoodoo spirit.)
Many blues lyrics, not just those by Robert Johnson, reference Hoodoo practices. See here: http://www.luckymojo.com/blues.html