EWI is a type of wind controller, an electronic musical instrument invented by Nyle Steiner. The EWI has been used by many artists across many different genres.

A wind controller, sometimes referred to as a wind synthesizer, is an electronic wind instrument. It is usually a MIDI controller associated with one or more music synthesizers. Wind controllers are most commonly played and fingered like a woodwind instrument, usually the saxophone, with the next most common being brass fingering, particularly the trumpet. Models have been produced that play and finger like other acoustic instruments such as the recorder or the tin whistle. The most common form of wind controller uses electronic sensors to convert fingering, breath pressure, bite pressure, finger pressure, and other gesture or action information into control signals that affect musical sounds. The control signals or MIDI messages generated by the wind controller are used to control internal or external devices such as analog synthesizers or MIDI-compatible synthesizers, synth modules, softsynths, sequencers, or even non-instruments such as lighting systems.