ROBERT JOHNSON (1911–1938), who ranks among the most influential and innovative American guitarists, played the Mississippi delta blues and was a major influence on early rock and rollers, especially the Rolling Stones and Eric Clapton. His intense slide-guitar and finger-style playing also inspired generations of blues artists, including Muddy Waters, Howlin’ Wolf, Bonnie Raitt, and Stevie Ray Vaughan. To get a sense of his style, visit the Internet Archive’s Robert Johnson collection: www.archive.org/details/RobertJohnsonMp3AudioSongs. Photo by Robert Johnson Estate/Hulton Archive/Getty Images