The bass guitar is a four-stringed instrument developed as a portable replacement for the traditional "stand-up," "upright" or "string" bass. As the lowest tuned instrument in the stringed instrument family, a bass guitar is used for low-note depth in music.

Origins

The bass guitar came along in the early 1950s, shortly after the electric guitar. The bass guitar was more portable than large, stand-up acoustic basses. It became popular with the smaller musical groups in the rock and country music genres.

Playing Style

The bass guitar is traditionally a back-up instrument, providing accompaniment to more melodic instruments. Jazz and rock bassists in the 1960s and 1970s experimented with the bass guitar as a solo and melodic instrument, prompting a new wave of popularity for the instrument.

Musical Styles

Although stand-up acoustic basses are still used for most every musical style, bass guitars are the dominant bass instrument for all styles, with the exception of symphony orchestras and traditional folk music.

More Strings

A traditional bass guitar has four strings; that's still the dominant type. Many modern rock and jazz players also use five and six string basses, which expand on the tonal range of the instrument.

Ease of Playing

Some newcomers to the bass have a false notion that the bass guitar is one of the easiest stringed instruments to learn. While some bass guitar styles are on the easy side, mastering the bass is as difficult as any musical instrument.

Source:

Collector's Weekly: About Vintage Bass Guitars

Hobgoblin: Bass Guitar Origins

Music Player: Bass Guitars

More Information:

Bass Player Magazine: Official Site

Harmony Central: Bass Guitar News and Resources