The bass guitar, electric bass or simply bass is the lowest-pitched member of the guitar family. It is a plucked string instrument similar in appearance and construction to an electric or acoustic guitar, but with a longer neck and scale length. The bass guitar most commonly has four strings, though five- and six-stringed models are also relatively popular, and bass guitars with even more strings or courses have been built. Since the mid-1950s, the bass guitar has largely come to replace the double bass in popular music due to its lighter weight, the inclusion of frets in most models, and, most importantly, its design for electric amplification. This is also due to the fact that the double bass is acoustically compromised for its range in that it's scaled down from the optimal size that would be appropriate for those low notes.

The guitar is a stringed musical instrument that is usually fretted and typically has six or twelve strings. It is usually held flat against the player's body and played by strumming or plucking the strings with the dominant hand, while simultaneously pressing selected strings against frets with the fingers of the opposite hand. A guitar pick may also be used to strike the strings. The sound of the guitar is projected either acoustically, by means of a resonant hollow chamber on the guitar, or amplified by an electronic pickup and an amplifier.