Bass guitar
A bass guitar is used to fill in the bottom end of music in many bands, and fills in the role that had tradionally been played by the Double Bass (often called a standup bass) in orchestras and bluegrass music. In most music, the beat of the bass guitar, together with the drums, is what an audience taps their feet to. In the traditional tuning used by most musicians for the 4-string bass guitar, the four strings are tuned just like the bottom (lowest notes, highest vertically) strings of a tradional six-string guitar. The popularity of bass guitars first became popular with the introduction of the Fender P-bass. Although bass guitars first started out as fretted electric models, recent decades have seen the acoustic bass guitar and the fretless bass guitar gain in popularity.
Tuning
Traditionally, the 4-string bass guitar is tuned, from lowest to highest (pitch), in E, A, D and G. Five-string bass guitars have an additional lower string tuned to B.