MS Technology Vocabulary MIDI

Jeffrey Fastow

January 2009

Computer 7-4

MIDI

MIDI or (Musical Instrument Digital Interface) is an industry standard protocol that allows electronic instruments, computers, synthesizers, MIDI controllers, sound cards, samplers and drum machines to communicate, control, and synchronize with each other. MIDI does not transmit media or audio messages, the software sends signals of audio intensity and pitch for the computer to recognize each note. With this method of transmitting, computers are able to pick up the vibrato and how loud each note is being played.

Messages

All MIDI compatible controllers, musical instruments, and MIDI-compatible software follow the same MIDI 1.0 specification, and thus interpret any given MIDI message the same way, allowing them to communicate with and understand each other. For example, if a note is played on a MIDI controller, it will sound at the right pitch on any MIDI instrument whose MIDI In connector is connected to the controller's MIDI Out connector.

When a musical performance is played on a MIDI instrument (or controller) it transmits MIDI channel messages from its MIDI Out connector.

Note-On, Aftertouch, and Note-Off are all channel messages. For the Note-On and Note-Off messages, the MIDI specification defines a number (from 0–127) for every possible note pitch (C, C#, D etc.), and this number is included in the message.

Other performance parameters can be transmitted with channel messages, too. For example, if the user turns the pitch wheel on the instrument, that gesture is transmitted over MIDI using a series of Pitch Bend messages (also a channel message). The musical instrument generates the messages autonomously; all the musician has to do is play the notes (or make some other gesture that produces MIDI messages). This consistent, automated abstraction of the musical gesture could be considered the core of the MIDI standard.

Composition

MIDI composition and arrangement takes advantage of MIDI 1.0 and General MIDI (GM) technology to allow musical data files to be shared among various electronic instruments by using a standard, portable set of commands and parameters. Because the music is simply data rather than recorded audio waveforms, the data size of the files is quite small by comparison. Several computer programs allow manipulation of the musical data such that composing for an entire orchestra of synthesized instrument sounds is possible. The data can be saved as a Standard MIDI File (SMF), digitally distributed, and then reproduced by any computer or electronic instrument that also adheres to the same MIDI, GM, and SMF standards. There are many websites offering downloads of popular songs as well as classical music in SMF and GM form, and there are also websites where MIDI composers can share their works in that same format.

Many people believe that the Standard MIDI File as a music distribution format used to be much more attractive to computer users before broadband internet became available to "the masses", due to its small file size. Also, the advent of high quality audio compression such as the MP3 format has decreased the relative size advantages of MIDI music to some degree, though MP3 is still much larger than SMF.

http://wiki.sjs.org/wiki/index.php/MS_Technology_Vocabulary [link title]

Edited by: Isabella Sturgis