Electric blues is blues music distinguished by the use of electric amplification for musical instruments. The guitar was the first instrument to be popularly amplified and used by early pioneers T-Bone Walker in the late 1930s and John Lee Hooker and Muddy Waters in the 1940s. Their styles developed into West Coast blues, Detroit blues, and post-World War II Chicago blues, which differed from earlier, predominantly acoustic-style blues. By the early 1950s, Little Walter was a featured soloist on blues harmonica using a small hand-held microphone fed into a guitar amplifier. Although it took a little longer, the electric bass guitar gradually replaced the stand-up bass by the early 1960s. Electric organs and especially keyboards later became widely used in electric blues.

Blues is a music genre and musical form that originated amongst African-Americans in the Deep South of the United States around the 1860s. Blues incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative ballads from the African-American culture. The blues form is ubiquitous in jazz, rhythm and blues, and rock and roll, and is characterized by the call-and-response pattern, the blues scale, and specific chord progressions, of which the twelve-bar blues is the most common. Blue notes, usually thirds, fifths or sevenths flattened in pitch, are also an essential part of the sound. Blues shuffles or walking bass reinforce the trance-like rhythm and form a repetitive effect known as the groove.