Musical Instrument Digital Interface (MIDI) is a standard electronic language used to communicate between electronic instruments and the computerized devices that control them during performances. This technology, which was developed in the early 1980s, allows a keyboardist to start a drum synthesizer with a single keystroke or a computer to save a sequence of composed notes as a MIDI file, for example. The same set of binary code instructions is recognized the keyboard, drum synthesizer, and computer.
Professional keyboardists used to have to set up towering banks of synthesizers, pianos, organs, and other electronics in order to perform live before the development of the MIDI system. They’d switch from instrument to instrument to get the sounds they needed. With the introduction of MIDI, these same musicians could use 5-pin DIN cables to connect all of the peripheral keyboards and control them all from a single master keyboard. Through a MIDI connection, a synthesizer set for background strings, for example, could “teach” another keyboard how to generate that sound.
However, this technology is not limited to musical synthesizers. Other types of stage equipment, such as lighting banks, are frequently controlled MIDI-compatible computers. A master program can be used to assign each light a specific channel and turn it on or off. These programs may also control guitarists’ effects pedals or pre-recorded sequences to augment the sound onstage.
The sound of the keyboard instrument is not recorded in MIDI files; rather, they contain instructions on how to recreate that sound elsewhere. A keyboardist, for example, might use a MIDI-compatible synthesizer connected to a computer to play Beethoven’s Moonlight Sonata. Each note would be converted into a series of 1s and 0s, similar to binary code. Other aspects of the performance, such as dynamics, note-bending, and changes in key pressure, are included in the coding.
The MIDI file would play exactly what the original keyboardist played on the original instrument if someone wanted to play that recorded version of the Moonlight Sonata on a different computer. It’s possible that the computer’s sound reproduction capabilities will cause a problem. A very weak-sounding version of the MIDI file may be rendered the computer’s sound generation card, along with some unpleasant electronic noises. Many of these issues have been solved modern computers with advanced sound cards, but many people still associate MIDI files with mediocre performance.
These files have become very popular for use on websites, video game programs, and MIDI-compatible cellular phones due to their small size and ease of production. Many cellphone ring tones are actually MIDI files that use the phone’s own sound card to reproduce the original tunes.