During the early 1970s, sounds generated by the electronic synthesizer became increasingly popular in recordings and at rock concerts. Gradually, these once prohibitively expensive musical instruments became commonplace and affordable. In addition to a great variety of user-friendly electronic keyboards on offer, there were related devices, such as sequencers, that could "trigger" sounds from a connected keyboard, as well as drum machines with a variety of sounds.
One problem that arose with this electronic proliferation was that devices produced by different manufacturers tended not to be compatible with each other. American audio engineer Dave Smith sought a way forward when, at a 1981 meeting of the Audio Engineering Society, he presented a paper that proposed the first universal communication standard for musical equipment. He called it MIDI—an acronym for Musical Instrument Digital Interface. In essence, MIDI is a digital "language" that enables synthesizers, MIDI recorders (whether hardware sequencers or computer-based software), drum machines, and other similarly equipped devices to "talk" to one another by sending and receiving messages via interconnecting MIDI cables. The simplest use of MIDI would be two synthesizers connected in such as way as to enable the sounds of both instruments to be played and controlled from just one of the keyboards.
Smith's paper was immediately adopted by manufacturers. Indeed, it would be no exaggeration to suggest that without MIDI most of the programmed and sampled electronic music of the past twenty-five years simply could not have been made.