MIDI

MIDI or Musical Instrument Digital Interface is a standard that describes a communications protocol, digital interface, and electrical connectors for electronic musical instruments and computers. 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. A MIDI recording is not an audio signal, as with a sound recording made with a microphone. It is more like a piano roll, indicating the pitch, start time, stop time and other properties of each individual note, rather than the resulting sound.

The term MIDI should not be confused with nor confined to specifically the file format used on the personal computer. Before the development of MIDI, electronic musical instruments from different manufacturers could generally not communicate with each other. MIDI was an entire platform approach to dealing with this problem by making it possible to connect instruments and have a standard way for them to communicate. For example, a music keyboard that can electronically play multiple electronic instruments.

Roland Corporation was a company started in the 1970s and their DCB was the basis for a universal interface to allow communication between music equipment from different manufacturers being the basis of MIDI. The MIDI Manufacturers Association (MMA) was formed in 1984 and by 1985 the MIDI 1.0 specification had been adopted. The standard continued to evolve, adding standardized song files in 1991 (General MIDI).

The MIDI file format was created to save the messages and information about an instruments notes and not the specific sounds that can easily be manipulated ranging from synthesized or sampled guitar or flute to full orchestra. The General MIDI (GM) standard was established in 1991, and provides a standardized sound bank that allows a Standard MIDI File created on one device to sound similar when played back on another. It uses a bank of 128 sounds arranged into 16 families of eight related instruments, and assigns a specific program number to each instrument.

MIDI became very popular for sharing musical information between similar applications and for transferring over low-bandwidth internet connections. The small size also allows for storing on small devices like floppy disks. WAV and MP3 files are larger and more difficult to edit than MIDI files. Since MIDI files are small and contain only the actual musical notes, they are the preferred format for writing and editing music electronically.