Introduction to MIDI – The 1981 Music Revolution

Who can remember what MIDI actually stands for?

The answer is Musical Instrument Digital Interface and yes, I had also forgotten.

The simplest way to describe it is that it is a standard communication protocol, or without using technical jargon, a language that electronic music instruments use to communicate with each other in order to send and receive musical instructions.

The specification has been around for decades, it was designed in the early 80s by Dave Smith and Chet Wood, then of Sequential Circuits. It quickly became widely adopted as a means for instruments from different manufacturers to communicate with each other. It’s still very widely used today, 40 years later.

The most common use for MIDI these days is probably connecting a USB MIDI controller keyboard to your PC and playing software instruments and recording the performances.

Most of us have probably seen these familiar round 5-pin MIDI DIN connectors. You need a pair of cables to allow for communication in both directions between two devices. Connect the MIDI OUT to the MIDI IN.

These days when connecting modern MIDI devices to a computer, it’s much more common and convenient to use a single USB cable to send and receive MIDI data.

If you need to connect older MIDI instruments to your computer then you’ll need a USB to MIDI interface to which you connect your old-school MIDI cables.  Some of the higher-end USB AUDIO interfaces also include DIN MIDI ports for this purpose.

MIDI data is a set of event messages or instructions for musical notation, for example, what notes to play and their velocity, meaning how soft or hard they are played which affects their volume and tone.

MIDI can also handle other types of musical data, such as program changes when selecting different sounds, and using sustain and expression pedals. It can also transmit and receive continuous controller data such as volume, panning, effects settings and all the knob turns you make when manipulating the front panel controls of a synthesizer.

MIDI can be captured in a MIDI sequencer and stored in a MIDI file and then played back, so all the MIDI events such as note-on and note-off are triggered at the right time.

MIDI supports 16 channels or tracks so you can build up multi-instrument performances.

It’s important to understand that MIDI data is very different to an audio signal that you might for example record with a microphone.

There are several advantages when working with MIDI. You can easily edit the captured MIDI events to fix wrong notes or timing. You can slow down or speed up the playback to change the tempo or transpose the entire performance. If you want to, you can switch out the instruments that are used. This would be impossible to do with an audio recording.

MIDI files are a fraction of the size of audio files, so ideal for sharing on the internet. Keep in mind though that the recipient will be playing back the MIDI through their own hardware or software devices in order to actually hear the music being played. If they don’t have the exact same devices it will sound quite different.

40 years later and MIDI is still going strong, with a new 2.0 specification on the horizon. Thank you to the inventors and the early adopters. It’s hard to imagine music creation without it.

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