The electric bass guitar is a stringed instrument which is like a guitar but with a deeper tone and which tends to serve as a bridge between instruments, helping punctuate time with the drums while providing the skeleton to a melody or progression which is fleshed out by guitar, piano, or any of a number of other instruments. It is ubiquitous in rock and roll, and often used in modern jazz, funk country, and disco.
Like the electric guitar, the vibrations of the string cause an electrical signal to be created in sensors called pickups, which are amplified and played through a speaker. Various electronic components, and the configuration of the amplifier and speaker, can be used to alter the sound of the instrument.
The bass guitar was invented in 1950 by Leo Fender, a well-known guitar manufacturer, as experiments with upright basses with pickups did not work very well at the time. The change to the guitar form factor and the addition of frets made the instrument much easier to play.
The bass guitar is usually a four-stringed instrument with the standard tuning E-A-D-G, though it sometimes has five or six strings. The additional strings, when present, will usually be tuned to B a fourth below the low E (B-E-A-D-G is the most common 5-string tuning), and C a fourth above the high G string (B-E-A-D-G-C is the most common 6-string tuning). The electric bass is most commonly a fretted instrument, which means that the neck of the bass is divided by slightly raised metal bars, or frets, marking the location of different notes. Each fret marks a note a half-step higher: for instance, playing the low E without holding the string down anywhere will produce an "E"; playing while holding the string down firmly between the first fret and the nut will produce a note a half-step higher ("F") and so forth.
Many artists, such as Pino Palladino utilize a fretless bass guitar for the smoothness of its slide and unique tone. As with any instrument, the electric bass can be played in a number of styles. Players such as Paul McCartney tend to favor a subdued, melodic approach, while Les Claypool of Primus and Flea of Red Hot Chili Peppers favor a funky, slap-heavy (sounding the notes by slapping the string with the thumb rather than plucking) approach earlier made popular by Larry Graham. Many players prefer to pluck the noted with the fingers, but for fast play (such as that required for punk rock) a pick is sometimes used.
The acoustic bass guitar is a larger instrument whose hollow interior acts to amplify the strings' vibration, thereby removing the need for external amplification, however many acoustic bass guitars retain pickups for conventional amplification and are used virtually identically to conventional electric models as, unamplified, they are too quiet to be heard properly.