Clapton believes Robert Cray did that better than anyone. “It’s the most difficult thing to write, a modern blues,” Clapton told Rolling Stone in 2017 mused. “The only person I know who can do it well is Robert Cray. Despite getting a metaphorical pat on the back from a blues legend, Cray wasn't a purist. While those two instances are comedic footnotes to a journeyman career, Cray is as authentic as modern blues can get.