An idiophone is any musical instrument that creates sound primarily by the vibration of the instrument itself, without the use of air flow (as with aerophones), strings (chordophones), membranes (membranophones) or electricity (electrophones). It is the first of the four main divisions in the original Hornbostel–Sachs system of musical instrument classification (see List of idiophones by Hornbostel–Sachs number). 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 (like the wood block, singing bowl, steel tongue drum, triangle or marimba) or indirectly, with scraping or shaking motions (like maracas or flexatone). Various types of bells fall into both categories. A common plucked idiophone is the Jew's harp.
are instruments made of naturally sonorous materials not needing any additional tension as do strings and drumskins. In this class it is the player's action that has shaped the instruments, because they have originated from extensions of striking or clapping hands or stamping feet. Accordingly, the basic question is how they are set into vibration.
Most percussion instruments that are not drums are idiophones. Hornbostel–Sachs divides idiophones into four main sub-categories. The first division is the struck idiophones (also known sometimes as concussion idiophones). This includes most of the non-drum percussion instruments familiar in the West. They include all idiophones made to vibrate by being struck, either directly with a stick or hand (like the wood block, singing bowl, steel tongue drum, triangle or marimba) or indirectly, by way of a scraping or shaking motion (like maracas or flexatone). Various types of bells fall into both categories.
The other three subdivisions are rarer. They are plucked idiophones, such as the Jew's harp, amplified cactus, kouxian, dan moi, music box and mbira (lamellophone or thumb piano); blown idiophones, of which there are a very small number of examples, the Aeolsklavier being one; and friction idiophones, such as the singing bowl, glass harmonica, glass harp, turntable, verrophone, daxophone, styrophone, musical saw, and nail violin (a number of pieces of metal or wood rubbed with a bow).
Other classifications use six main sub-categories.
- Concussion idiophones are instruments that produce sound by being struck against one another.
- Percussion idiophones produce sound by being struck with a non-vibrating foreign object. Examples of non-vibrating objects are mallets, hammers, and sticks.
- Rattle idiophones are shaken.
- Scraper idiophones are instruments that are scraped with a stick or other foreign objects to give off a sound.
- Plucked idiophones produce sound by plucking a flexible tongue from within the instrument itself.
- Friction idiophones are rubbed to increase vibration and sound intensity.
For example, a pop toob is a brand name for a noisemaker or musical instrument consisting of tubes that are extendable, bendable, and connectable, with the noise being created concussively by the bending and unbending, or popping, of the tube's corrugation, whereas a whirly tube uses corrugated tubing and the difference in speed and thus air pressure to create an aerophone when spun in a circle.
- Sachs, Curt (1940). The History of Musical Instruments, p.455. W. W. Nortan & Company, Inc. ISBN 0-393-02068-1
- "idio-". Etymology Online. Retrieved 9 January 2019.
- "-phone". Etymology Online. Retrieved 9 January 2019.
- Don Michael Rendel, ed., The New Harvard Dictionary of Music, 1986.
- "Idiophones", The Most Comprehensive Music Technology Glossary. Archived 2009-12-17 at the Wayback Machine
- United States. Patent and Trademark Office (1995). Official Gazette of the United States Patent and Trademark Office: Trademarks, Volume 1176, Issue 1, p.288. U.S. Department of Commerce, Patent and Trademark Office.  and .