Musical Instrument Digital Interface (MIDI)

Understanding Musical Instrument Digital Interface (MIDI)

  • MIDI, or Musical Instrument Digital Interface, is a standard protocol for the interchange of musical information between digital instruments, computers, and other related devices.
  • It does not transmit actual sounds, but digital data, which encodes instructions to generate the sound elsewhere.
  • It was first developed in the 1980s to enable electronic musical instruments and computers to communicate with each other.
  • MIDI allows devices to send messages to each other, detailing aspects such as pitch, volume, velocity, vibrato, and clock signals, allowing synchronisation.

The MIDI Protocol

  • The MIDI Protocol is based on asynchronous serial transmission. It uses digital communication techniques to transmit messages in binary form.
  • MIDI messages start with a status byte, followed by a series of data bytes.
  • The status byte typically indicates which type of event to execute, such as note on or note off.
  • This is followed by one or more data bytes that provide additional information, such as the pitch of the note and the velocity of the note-on event, i.e., how hard a key is struck on a keyboard.
  • MIDI messages include both channel messages and system messages. Channel messages are intended for a specific device, whereas system messages are common to all devices on a MIDI network.

MIDI Interfaces

  • MIDI interface is a physical connector that allows a MIDI instrument to connect to a computer or another MIDI instrument.
  • Common MIDI interface forms include the traditional 5-pin DIN connector, USB MIDI, and FireWire MIDI.

MIDI Files

  • MIDI files store sequences of MIDI data. These files can be sequenced or composed in music editing software, and played back on any MIDI-compatible device.
  • A typical MIDI file contains one or more MIDI streams, with time information for each event. This format is called Standard MIDI File (SMF).
  • The part of the MIDI file that contains actual MIDI events to control the music is called a track chunk.

Importance of MIDI in Computing

  • MIDI has become a standard in the music industry, playing a crucial role in music production, songwriting, live performances, and movie soundtracks.
  • It allows for digital composition, arrangement, alteration, and performance, allowing the capture of the artist’s intent and the ability to modify it post-performance.
  • MIDI is also used for communication in multimedia applications, allowing computers to control lighting systems, sound devices, and other equipment.
  • Understanding MIDI and its data representation is critical for a career in technology aspects of music production, video games, and interactive multimedia design.