Few artists left such a vital body of work while leaving so little information about their lives as Delta blues king Robert Johnson. The man from Mississippi only recorded 29 songs before his death in 1938, aged just 27. Blues mythology says he sold his soul to the devil in order to master the guitar, and his haunted moan, dark tales and fiery fingers gave the story traction. Only a few songs were released during his lifetime, and sales were moderate. But he became a posthumous star in 1961 thanks to a Columbia Records compilation that went on to inspire a generation of British rock icons.