MIDI is an acronym for Musical Instrument Digital Interface. It was introduced in 1983 and is a standard for communication between musical instruments and electronic devices.
Accordions can be made with MIDI controls integrated or MIDI can be added to most already existing accordions. MIDI has many applications, including storing what is played by the live performer to computer, enabling scores to be printed. MIDI files can also be played on most computers which have a sound card. Another use of MIDI is in show control and in using digital effects with the accordion in live performance.