A bass guitar is a stringed instrument designed for playing the lower notes in a piece of music. In a band or ensemble, the bass guitar generally plays an accompaniment to the lead guitar. A bass guitar can be acoustic, semi-acoustic, or electric and though similar to a guitar, the bass guitar has a few major differences.

Instead of the standard six strings of a guitar, the bass guitar generally has four strings, though there are models with five or more strings. The four strings of a bass guitar are tuned to E-A-D-G from lowest to highest and are typically tuned with E at 41.3 Hz. Though some bass guitars have no frets, most are fretted with 24 frets to achieve a range of at least two octaves per string.

The semi-acoustic and electric bass guitars are the most commonly played basses. The development of the electric bass guitar began with the jazz era sometime in the early 20th century. In orchestral music, several bass players combined and created the sounds of the bass accompaniment. As jazz music evolved, musicians sought a way for a single musician to play the bass accompaniment so that it could be heard without being drowned out by the other instruments.

Today, the electric bass guitar is an instrument most always found in live bands performing classic and southern rock, heavy metal, jazz, and blues music. Both semi-acoustic and electric bass guitars can be played with various amplifiers depending on the setting. A semi-acoustic bass guitar is hollow in the middle, which achieves resonance for sound without an amplifier, but it has electrical components in the neck so that it can also be played with an amplifier, making it a versatile choice for bass.

The type of bass guitar a musician chooses is based largely on personal preference and the sound they desire to achieve. Each part of a bass guitar -- the neck, the body, and the pickups -- can be unique to each brand's design. Most bodies are made of wood such as mahogany or alder and are lacquered or waxed to enhance the wood grain. Design and color are nearly as important as sound quality to many bass guitar players.