The bass guitar, electric bass (or simply bass) is the electric alternative to the double bass. It is a plucked string instrument similar in appearance and construction to an electric or an acoustic guitar, except with a longer neck and scale length, and typically four to six strings or courses. Since the mid-1950s, the electric bass has largely replaced the double bass in popular music. The four-string bass is usually tuned the same as the double bass, which corresponds to pitches one octave lower than the four lowest-pitched strings of a guitar (E, A, D, and G). It is played primarily with the fingers or thumb, or striking with a pick. The electric bass guitar has pickups and must be connected to an amplifier and speaker to be loud enough to compete with other instruments.