The marimba, is a musical instrument in the percussion family that consists of wooden bars that are struck by mallets. Below each bar is a resonator pipe that amplifies particular harmonics of its sound. Compared to the xylophone, the marimba has a lower range. Typically, the bars of a marimba are arranged chromatically, like the keys of a piano. The marimba is a type of idiophone.

An idiophone is any musical instrument that creates sound primarily by the vibration of the instrument itself, without the use of air flow, strings (chordophones), membranes (membranophones) or electricity (electrophones). It is the first of the four main divisions in the original Hornbostel–Sach system of musical instrument classification. The early classification of Victor-Charles Mahillon called this group of instruments autophones. The most common are struck idiophones, or concussion idiophones, which are made to vibrate by being struck, either directly with a stick or hand or indirectly, with scraping or shaking motions. Various types of bells fall into both categories. A common plucked idiophone is the Jew's harp.