Glossary definition of 'Musical Instrument Digital Interface'
A digital serial interface standard designed to transmit and receive musical note information between electronic musical instruments. Rather than transmit audio, it transmits data about note on and note off events which the receiving equipment is expected to interpret. Since its inception, its usage has expanded to a far wider range of applications from transferring system information and control information to being used for equipment software upgrades, show control and time code. Although the MIDI standard defines a wired interface with an opto-isolated 5 pin 180 degree DIN connector, variants of the MIDI protocol are increasingly being sent down other connections such as Ethernet, USB and FireWire.