Bass guitars have similar design features to other types of guitar but scaled up: thicker strings, longer neck and larger body, etc. This allows lower notes to be created when the strings are tuned to a playable tension. They are sometimes categorized as guitars but are also categorized as a separate instrument.
Although there are many variations, the standard bass guitar has four strings tuned EADG, from lowest pitch string to highest, one octave lower than the bottom four strings of a guitar in standard tuning. The next most common variant is the five string, tuned BEADG. While the bass guitar can be played like an oversized guitar, by playing chords, this chordal style is rare on bass. Rather, bass is often used to play single notes. Bass also draws much inspiration from double bass playing, notably the smooth quarter note style calked "walking bass" which is used in jazz, blues and country. The electric bass has a vocabulary of playing styles and music all of its own, including slapping and popping.
Slapping And popping
One of the distinguishing features of the bass guitar is the percussive slap style. It is most associated with funk, but it is also used in sone pop, jazz fusion and nu metal styles. It is typically distinct to the bass guitar, although it has been used on acoustic guitars by skillful players.
Slapping is accomplished by percussively striking the string - usually E or A on a standard tuned bass - with the left hand side of the thumb (for a right-handed player). This is done towards the neck of the bass. The thumb is then pulled away as quickly as possible, to create a distinct, "fretty" noise.
Popping is accomplished by curling the fingertip of the index or middle finger under the string - usually the D or G string. The string is then plucked to create a similar sound to slapping on the thicker strings. This is, again, performed towards the neck of the bass. Fretting hand and playing hand muting and percussive "ghost notes" are a key part of the distinctive sound of slapping and popping.
The "standard" bass is a 4 string bass, tuned EADG (low to high). Other variations of this tuning include DADG ("drop D") and rarely iiCGCF. These lower tunings are often used in metal and heavier music, as they extend the instrument's range lower. Altering the tuning of a bass to a lower range (or any other fretted instrumented) by reducing string tension can cause problems that new players should be aware of: looser strings are more prone to "fret buzz", in which a string rattles on the fretboard, producing a sound that is usually unwanted. Loosening strings also alters the tension on the neck, which can lead to warping the neck.
To achieve a clear tone on notes lower than standard tuning, a standard five string bass adds a low B string, with the bass normally tuned BEADG (low to high). Some players may restring a 4-string bass as BEAD, leaving off the high G. There are thick strings that go even lower in range, however these are typically found only on specialty instruments.
Bass runs or "fills" are used to add interest and to transition frommone chord to another. For example if one wants to change from a C chord bassline to an Am chord bassline, they could do a scalar run that adds a B note to connect the C to the A.