The bouzouki is a Greek musical instrument that was brought to Greece in the 1900s by Greek immigrants from Asia Minor, and quickly became the central instrument to the rebetika genre and its music branches. A mainstay of modern Greek music, the front of the body is flat and is usually heavily inlaid with mother-of-pearl. The instrument is played with a plectrum and has a sharp metallic sound, reminiscent of a mandolin but pitched lower. There are two main types of bouzouki. The trichordo (three-course) has three pairs of strings (known as courses), and the tetrachordo (four-course) has four pairs of strings.