Robert Nighthawk.

“Robert Nighthawk was one of the Delta’s most famous blues artists during the 1940s and ‘50s, known for his radio broadcasts on KFFA in Helena, Arkansas, and WROX in Clarksdale, as well as for his recordings and his wide-ranging travels.”
“Nighthawk was famed for his cool, composed vocal style and his influential slide guitar sound, which he achieved by sliding a piece of brass pipe along the guitar frets. His best known records included “Annie Lee Blues,” “Black Angel Blues,” “The Moon is Rising,” and “Crying Won’t Help You.” B.B. King once named Nighthawk as one of his ten favorite guitarists. Nighthawk’s renown has spread internationally since his death in Helena on November 5, 1967. He was elected to the Blues Hall of Fame in 1983, and a powerful album released in 1980, Robert Nighthawk: Live on Maxwell Street 1964, was named one of the ten best rock ‘n’ roll albums of the year by critic Greil Marcus.” - Mississippi Blues Trail.