MIDI stands for Musical Instruments Digital Interface.

Since its launch in 1982 MIDI has established itself as the standard for exchanging musical control signals between electronic instruments such as synthesizers or samplers. MIDI was originally designed to allow a synthesizer keyboard to be used to control other synthesizers.

When a key is pressed, digital information about the pitch and duration is transmitted via the MIDI interface to control computer recording software, another synthesizer or other sound generator (sampler).