The vibraphone, sometimes called the vibraharp or simply the vibes, is a musical instrument

Musical instrument

A musical instrument is a device created or adapted for the purpose of making musical sounds. In principle, any object that produces sound can serve as a musical instrument—it is through purpose that the object becomes a musical instrument. The history of musical instruments dates back to the...

 in the struck idiophone subfamily of the percussion

Percussion instrument

A percussion instrument is any object which produces a sound when hit with an implement or when it is shaken, rubbed, scraped, or otherwise acted upon in a way that sets the object into vibration...

 family.

The vibraphone is similar in appearance to the xylophone

Xylophone

The xylophone is a musical instrument in the percussion family that consists of wooden bars struck by mallets...

, marimba

Marimba

The marimba is a musical instrument in the percussion family. It consists of a set of wooden keys or bars with resonators. The bars are struck with mallets to produce musical tones. The keys are arranged as those of a piano, with the accidentals raised vertically and overlapping the natural keys ...

 and glockenspiel

Glockenspiel

A glockenspiel is a percussion instrument composed of a set of tuned keys arranged in the fashion of the keyboard of a piano. In this way, it is similar to the xylophone; however, the xylophone's bars are made of wood, while the glockenspiel's are metal plates or tubes, and making it a metallophone...

 but uses aluminum bars; not wood

Wood

Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

en bars like the first two instruments. Each bar is paired with a resonator tube having a motor-driven butterfly valve

Butterfly valve

A butterfly valve is a valve which can be used for isolating or regulating flow. The closing mechanism takes the form of a disk. Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they are lower in cost to other valve...

 at its upper end, mounted on a common shaft, which produces a tremolo or vibrato effect while spinning.