early electric slide guitarists When the guitar was electrified in the 1930s, it allowed solos on the instrument to be more audible, and thus more prominently featured. In the 1940s, players like Robert Nighthawk and Earl Hooker popularized electric slide guitar; but, unlike their predecessors, they used standard tuning. This allowed them to switch between slide and fretted guitar playing readily, which was an advantage in rhythm accompaniment. Robert Nighthawk Robert Nighthawk (born Robert Lee McCollum) recorded extensively in the 1930s as "Robert Lee McCoy" with bluesmen such as John Lee "Sonny Boy" Williamson (also known as Sonny Boy Williamson I). He performed on acoustic guitar in a style influenced by Tampa Red. Sometime around World War II, after changing his last name to "Nighthawk" (from the title of one of his songs), he became an early proponent of electric slide guitar and adopted a metal slide. Nighthawk's sound was extremely clean and smooth, with a very light touch of the slide against the strings. He helped popularize Tampa Red's "Black Angel Blues" (later called "Sweet Little Angel"), "Crying Won't Help You", and "Anna Lou Blues" (as "Anna Lee") in his electric slide style-songs which later became part of the repertoire of Earl Hooker, B.B. King, and others. His style influenced both Muddy Waters and Hooker. Nighthawk is credited as one who helped bring music from Mississippi into the Chicago blues style of electric blues. Earl Hooker As a teenager, Earl Hooker (a cousin of John Lee Hooker) sought out Nighthawk as his teacher and in the late 1940s the two toured the South extensively. Nighthawk had a lasting impact on Hooker's playing; however, by the time of his 1953 recording of "Sweet Angel" (a tribute of sorts to Nighthawk's "Sweet Little Angel"), Hooker had developed an advanced style of his own. His solos had a resemblance to the human singing voice and music writer Andy Grigg commented: "He had the uncanny ability to make his guitar weep, moan and talk just like a person... his slide playing was peerless, even exceeding his mentor, Robert Nighthawk." The vocal approach is heard in Hooker's instrumental, "Blue Guitar", which was later overdubbed with a unison vocal by Muddy Waters and became "You Shook Me". Unusual for a blues player, Hooker explored using a wah-wah pedal in the 1960s to further emulate the human voice. Elmore James Possibly the most influential electric blues