A Brief History of MIDI

Bob Leggitt | Sunday, 18 March 2012
MIDI sockets on a 1990s hardware sequencer

For just over a decade between the mid ‘eighties and the mid ‘nineties, MIDI was the be-all-and-end-all of so many amateur musicians’ creative lives. In fact, MIDI is still one of the most important elements in today’s commercial music. It’s just that it does its job a lot more stealthily these days, and it’s part of a wider raft of options for all amateur musicians.

Musical Instrument Digital Interface first began to see use during the early 1980s, in relatively simple form, essentially as a method of chaining together synthesizers (not necessarily digital synthesizers), so that one could be operated remotely, from the keyboard of another. Known as MIDI (pronounced “middie”), the new digital communication method sent computerised instructions down a physical wire from one musical instrument to the next. In the early days, the typical user would employ MIDI to layer up synth sounds, in unison, one on top of the other. The keyboardist would play a part on one synth, and MIDI would send the digital blueprint of his/her actions to one or more other synth(s), which would duplicate what he/she was playing.

Why did synth players do this? Well a) because they could, and they’d never been able to do so before, so it was a novelty; and b) because synthesizers in the early to mid ‘eighties were still pretty limited as stand-alone instruments. The new digital models may have been impressive in their accuracy when it came to simulating the character of ‘real’ instruments, but they were weak and quite thin-sounding in their execution. Stacking up the sounds of several of these synths for a thicker composite tone did make sense, even beyond the novelty value.

Subsequently, however, a broader view of MIDI and its capabilities emerged, as the first dedicated MIDI sequencers hit the market, starting in 1984, with Roland’s MSQ-700. Sequencing was simply a method of automating the playback of an instrument. The concept could be traced right back through the centuries to mechanically automated instruments such as barrel organs or player pianos. Indeed, even electronic sequencing had been used heavily in music long before MIDI sequencers became available. The sequence (the electronic or digital instruction set for the automation) could be programmed – entered manually into the sequencer, note by note or pulse by pulse.

It could also be recorded. Recording a sequence was just like using a tape recorder. You played a musical passage on an instrument (normally a keyboard instrument) which was linked to a sequencer, and the sequencer recorded what you played. However, the sequencer didn’t record the actual sound – only the instruction set relating to what you played. It would record the fact that you’d pressed a key on the keyboard, for instance, or the fact that you’d released it. But it wouldn’t record an audible note. When the sequencer played back the recorded instructions, the keyboard’s electronic or digital sound engine would theoretically respond just as it would were a human being physically pressing the keys. The sound was 100% live, because it was being produced by the synth, in the moment. But it was being played by a machine, as opposed to a human being.

With MIDI sequencing, the often overwhelmingly robotic character of older electronic music steadily began to disperse. The ability of digital synths to more accurately replicate ‘real’ instrument sounds, along with the more intricate editing facilities being developed for desktop computers, made sequenced music viable for a much wider range of genres. Particularly once popular digital synths began to incorporate audio samples of genuine ‘real’ instruments into their sound generator chips, sequenced music truly began to shake off its electronic personality. By the end of the 1980s it was difficult to tell which tracks were MIDI-sequenced, and which ones were traditional audio recordings.

But why record an instrument to a MIDI sequencer at all? Three main reasons:

1. Live and completely lossless sound quality.

2. Multi-tracking potential.

3. Editing facilities would permit the correction of mistakes.

MIDI merge box
How many readers remember using these things? The MIDI merge box would take MIDI feeds from two separate instruments, and merge them into a single cable feed. Annoyingly necessary for certain applications - especially annoying given that they weren't particularly cheap.

In the 1980s, almost all amateur recordings, as well as a very large number of professional ones, were captured on analogue audio tape. Tape noticeably degraded the sound quality, and so live music was always preferable. But sequenced MIDI, even though the automation was recorded, still had completely live sound. MIDI was thus a means of lossless recording in an era before lossless audio recording became widely available. And because more than one MIDI instrument could be sequenced at the same time, MIDI also facilitated multi-tracking. Using a collection of MIDI-equipped instruments, and a sequencer which could automate each of them independently, a musician had what was tantamount to a recording studio. A recording studio which maintained perfect sound reproduction upon playback, and which could be employed on stage at gigs – without any need for the musician(s) to sacrifice that all-important term: ‘live’. 

But buying numerous synthesizers plus a drum machine was costly, and beyond the means of many amateur musicians. Synth manufacturers had accordingly realised early on that if they could make one synth capable of playing the sounds of several different instruments simultaneously, then in combination with a MIDI sequencer, this multitasking synth would become the Holy Grail. Enter the multitimbral synthesizer.

Because the concept of multitimbrality (this ability for a synth to multitask with instrument sounds) went above the heads and beyond the pockets of most musicians in the early days of MIDI, the market-leading synths generally remained monotimbral. Yamaha’s top-selling DX7 could only play a single MIDI sequence at a time until its revamp in 1987 (afterwhich it could play two). Yamaha did offer eight part multitimbrality in their TX816 module (a module being a synth without the keyboard) from 1985, but the unit was prohibitively expensive for the average musician of the day, who in any case, really needed the concept to be spelled out a lot more clearly.

Korg did that in fine style with their M1 digital workstation in 1988. A workstation was the next step forward in MIDI integration, incorporating the actual sequencer into the keyboard. So now, a musician could buy one piece of gear, and have a whole band’s worth of potential at his or her fingertips. Drums, bass, brass, pianos, strings – hundreds of instrument sounds, accurate for their time, all with the potential to be independently played into an eight track, lossless recording, without even leaving the confines of the synthesizer. In just a few years, MIDI had come a long way.

From that point forward, there was a steady migration of sequencing duties from dedicated hardware, to a desktop computer. The primary reason for this was the massively increased scope for editing offered by computers. A hardware sequencer wasn’t greatly user-friendly with its push-button interface and small LCD screen. But a computer, with its large visual display and mouse functions, meant that musicians could pull up comprehensive visual representations of each track on a monitor, then precision-edit small details until everything was absolutely perfect. The more mistakes you typically made, the more important it was that you used a desktop computer for sequencing. By the mid 1990s, the majority of MIDI sequencing was being carried out on computers, and hardware sequencers were fading from view. The sounds themselves were still generally being reproduced by dedicated outboard synths or beat boxes, connected to the computer via a MIDI interface. Soundcards could play back MIDI recordings, but the available sounds were normally grossly inferior to those in the hardware synths of the day.

[UPDATE: The example sound stream was hosted on Tindeck. Since Tindeck closed in 2018, the stream is now inoperable..]
Above: A recording made in the 1990s entirely using live MIDI hardware instruments, sequenced from a 486 PC. Instruments employed in the track include: Boss DR-660 drum machine, Hammond XM1 organ module, Korg X5 Synthesizer, Korg Prophecy Solo Synth, Korg 05R/W synth module, Alesis Nano Piano. The live multitrack run was captured on Type II audio tape, via a standard Yamaha stereo cassette deck.

But as computers became more powerful, the concept of the virtual instrument came to the fore, and eliminated the need for outboard synthesizers entirely. The virtual instrument would use the computer’s processing resources to model the sound and functions of a real piece of hardware. The sounds from virtual instruments could be incredibly convincing, because the characteristics of real musical instruments could be simulated just as they would be in a powerful digital synthesizer. The more resources computers were able to offer, the more accurate virtual instrument sounds would technically become.

And how were/are virtual instruments recorded? Using MIDI. A note is played on an input keyboard, sending a MIDI signal to the computer and registering an automation instruction, whilst sounding a note using the virtual instrument for monitoring purposes. On playback, the MIDI automation instructions are sent directly to the virtual instrument rather than to a hardware keyboard outside the computer. But the principle is exactly the same. When you use any of the free virtual VST instruments available from this site, you’re using the exact same recording process as wealthy, tech-aware musicians were employing in the mid ‘eighties with their TX816s and banks of eye-wateringly expensive keyboards.

For many years now, practically lossless audio recording has been easily possible on even the cheapest of computers, so for some, MIDI doesn’t have the OMG factor it once did. And it’s true - you don’t see the cables connecting everything together in the PC’s virtual recording environment, so the role of MIDI is sometimes a lot less conspicuous. But if you do use virtual instruments, you’re reaping the benefits of that simple but earth-shatteringly significant ‘80s technology, hand in hand with some more recent developments. Until you mix to an audio file, your virtual instruments are being driven by the age-old language of MIDI. Still there, strong and important as ever.