
Ī MIDI recording is not an audio signal, as with a sound recording made with a microphone. The specification originates in the paper Universal Synthesizer Interface published by Dave Smith and Chet Wood of Sequential Circuits at the 1981 Audio Engineering Society conference in New York City. MIDI ( / ˈ m ɪ d i/ Musical Instrument Digital Interface) is a technical standard that describes a communications protocol, digital interface, and electrical connectors that connect a wide variety of electronic musical instruments, computers, and related audio devices for playing, editing, and recording music.

This system fits into a single rack case, but before the advent of MIDI, it would have required four separate full-size keyboard instruments, plus outboard mixing and effects units. Using MIDI, a single controller (often a musical keyboard, as pictured here) can play multiple electronic instruments, which increases the portability and flexibility of stage setups.
