The acoustic bass guitar (sometimes shortened to acoustic bass or initialized ABG) is a bass instrument with a hollow wooden body similar to, though usually larger than, a steel-string acoustic guitar. Like the traditional electric bass guitar and the double bass, the acoustic bass guitar commonly has four strings, which are normally tuned E-A-D-G, an octave below the lowest four strings of the 6-string guitar.
Because it can sometimes be difficult to hear an acoustic bass guitar without an amplifier even in settings with other acoustic instruments, most acoustic basses have pickups, either magnetic or piezoelectric or both, so that they can be amplified with a bass amp.
Traditional music of Mexico features several varieties of acoustic bass guitars, such as the guitarrón, a very large, deep-bodied Mexican 6-string acoustic bass guitar played in Mariachi bands, the león, plucked with a pick, and the bajo sexto, with six pairs of strings.