Guitar, both acoustic and electric, plays an important role in blues music, with players such as Blind Lemon Jefferson and Robert Johnson defining the style in the 1920s and 1930s. The image of an African-American man sitting on his front porch with a guitar in hand is one of the most prominent in blues lore. Slide guitar, called bottleneck in the early days of blues guitar style, remains a strong playing style in blues music.
Bass, whether electric or stand-up (acoustic) is a driving force behind blues music, Bass players often play walking bass or other repetitive patterns over the course of the 12 bars, providing a foundation for the typical off-the-cuff improvisations of guitar and piano players.
While the electric keyboard has found its way into more recent styles of the blues, the traditional acoustic piano still holds a key place in the genre. Pianos function both rhythmically and as lead instruments in blues music, with piano players often alternating solos or even sharing dual solos with guitar players.
A variety of drum and percussion setups are used in the blues; however, drum kits are typically reserved for more modern blues in band situations. Some small blues combos make use of simple drum kits, but many of the smaller combos (trios without drums, for instance) rely on bass and piano to perform the timekeeping role of the drum set.
The harmonica, referred to as a harp or blues harp, is one of the instruments longest used in the blues. The harmonica can be heard in blues going back to the roots of the music in the deep South, when it was the only instrument many early blues players could afford to own.