fender jazz bass

In jazz, the double bass is usually played with amplification and it is most played with the fingers, pizzicato style, except during some solos, where players may use the bow. The pizzicato style varies between different players and genres. Some players perform with the sides of one, two, or three fingers, especially for walking basslines and slow tempo ballads, because this is purported to create a stronger and more solid tone. Some players use the more nimble tips of the fingers to play fast-moving solo passages or to pluck lightly for quiet tunes. The use of amplification allows the player to have more control over the tone of the instrument, because amplifiers have equalization controls which allow the bassist to accentuate certain frequencies (often the bass frequencies) while de-accentuating some frequencies (often the high frequencies, so that there is less finger noise).

An unamplified acoustic bass' tone is limited by the frequency responsiveness of the instrument's hollow body, which means that the very low pitches may not be as loud as the higher pitches. With an amplifier and equalization devices, a bass player can boost the low frequencies, which evens out the frequency response. As well, the use of an amplifier can increase the sustain of the instrument, which is particularly useful for accompaniment during ballads and for melodic solos with held notes.Like other acoustic instruments used with amplification, such as the jazz violin, a double bass is often plugged into a preamplifier, impedance-matching device, and/or a Direct Injection (DI box) box before it is routed to the PA system, electronic effects, or the bass instrument amplifier.

An example of pizzicato jazz bass technique.

In traditional jazz and swing it is sometimes played in the slap style. This is a vigorous version of pizzicato where the strings are "slapped" against the fingerboard between the main notes of the bass line, producing a snare drum-like percussive sound. The main notes are either played normally or by pulling the string away from the fingerboard and releasing it so that it bounces off the fingerboard, producing a distinctive percussive attack in addition to the expected pitch. Notable slap style bass players, whose use of the technique was often highly syncopated and virtuosic, sometimes interpolated two, three, four, or more slaps in between notes of the bass line.