Since its inception a decade ago, MIDI has surprised many with its longevity and adaptability, largely re-inventing itself in response to changes in the needs of musicians and manufacturers. Craig Anderton documents some of the changes that have already occurred and some which are on the way — and explains why he believes MIDI 2.0 is already here.

Things are really starting to get out of hand. It was improbable in 1983 that manufacturers from competing companies and cultures could get together and agree on a specification. It was miraculous that companies actually adopted the spec, and created gear that all worked together. And it's almost beyond belief that MIDI is getting rediscovered as something seemingly brand new by a generation of multimedia PC enthusiasts.

But what really boggles the mind is that, 10 years after MIDI was introduced, it is gaining momentum — not losing it. This is a testimony to those who conceived the original spec and wisely left in the room for extensions; but it's also a testimony to an industry that has kept the trust of the music buying public by maintaining downward compatibility between new and old MIDI gear.

Changes to the spec have been made over the years in an orderly, deliberate fashion via the MMA (MIDI Manufacturers Association). The IMA Bulletin, edited by Lachlan Westfall, disseminates information to the public and also serves as a forum for MIDI ideas. Credit too must also go to PAN, the Performing Artists Network BBS by Perry Leopold, which links much of the MIDI community together via e-mail.

CONNECTING ANOTHER EXTENSION

And now, we have 'MIDI 2.0' to celebrate. Well, not really — it's still called MIDI 1.0. But in truth, the only similarity between the MIDI of 1993 and 1983,is that most devices built in 1983 still work with the 1993 stuff — that's about it.

There are so many extensions to the MIDI spec that if MIDI was under the aegis of someone's marketing department, it would probably be up to MIDI 5.0 by now. All the people who have been asking for 'MIDI 2.0' essentially have it — something with vastly more applications, speed, and usability than anyone ever dreamed possible back in the days of MIDI's creation. We'll get into the goodies a bit later, but first...

HIT AND MYTH

MIDI has been a big hit, but it has also been the subject of nasty rumours and complaints — like talk of a delay through the MIDI Thru port (wrong).

"MIDI's too slow": A lot of people still say this, but the fact is that it's the sound generating equipment more than MIDI that causes perceptible delays. I've been using Sound Tools to test the timing delays of various pieces of gear, and found typical delays to be in the 3ms to 10ms range to process a single MIDI note-on command, which only lasts 1ms. Therefore, with a 6ms delay (about average), MIDI is only accounting for 16% of the delay; the rest is the fault of the synthesizer. The more notes you play, the more the delays add up.

Manufacturers are doing what they can to speed up synth responses (matters are improving; the slowest synths often turn out to be the oldest ones). But there are certain practical and financial limits. You could double the speed of an instrument — not a trivial undertaking — and with a typical instrument MIDI would still only account for less than a third of the delay. So, let's not worry about whether MIDI's fast enough until we have instruments that can handle the higher speed.

Not enough channels; True, the original MIDI spec only had 16 channels. But there are so many ways to add channels — from syncing sequencers together to using multi-port computer interfaces — that there really isn't any need to run out of channels either.

For those who truly need more than just higher speeds and more channels. Lone Wolf has produced a LAN chip that allows MIDI gear to be part of a high-speed local area network. The transfer rate of MIDI data becomes a bottleneck only at the server level, which translates the high-speed network data into something individual pieces of MIDI gear can handle.

The only other real complaint about MIDI is that it still does not allow for bi-directional communication (except in very primitive ways). However, a single line of communication can do enough that we probably shouldn't get too upset.

THE WAY WE WERE

It's hard to believe, but many things we take for granted nowadays were not in the original MIDI spec.

• Standard MIDI Files: Being able to transfer MIDI files between different computer platforms via disk or modem turned out to be a breakthrough. Although implemented in much gear, unfortunately not all elements of the spec have been embraced — for example, SMFs include provisions to standardise patch data into a standard file format but this part is woefully underused.

• Sample Dump Standard: It's slower than molasses, but at least you can get digital audio data interchanged between various samplers. Some people complain because only the samples and loop points are transferred back and forth, not the signal processing parameters (filters, envelopes, and so on; this does a sort of automatic copy protection since people can't take a polished sound). But considering the chaos in digital audio standards, I'm just as glad there's at least some way we can get the really important stuff through. Although not all samplers implement this, it has had a reasonable impact.

• MIDI Time Code: All professional Macintosh sequencers rely on MTC for synchronisation, and instruments like the Emulator III let you create cue lists triggered by MTC timing. A boon to video and audio-for-video people, MTC was slow to take off but is now everywhere.

There have also been numerous other small enhancements. Recently, though, there have been two more biggies.

THE WAY WE ARE

• MIDI Machine Control: MMC is the culmination of a quest to merge MIDI sequencing and audio tape so that tape recorders become, essentially, MIDI system peripherals. MMC got off the ground at the October 1987 AES, largely through the work of Gerry Lester (formerly with Adams-Smith) but with extensive input from other industry people. Lester revised the proposal five times himself, but TEAC's Shoji Fujiwara, chairman of the Japan MIDI Standards Committee working group for the MMC, revised the spec from 1989 to 1991. MMC has the potential to extend MIDI's reach into the project and pro studio even further than it is now. Also of note: it's video/CD-ROM/multimedia-ready.

• MIDI Show Control: Originally proposed by Charlie Richmond (of Richmond Sound Designs, Vancouver, BC), MSC uses MIDI messages to control theatrical, live performance, and similar equipment — lights, strobes, lasers, CD players, rigging, special audio effects, animation, video switchers, projectors, and even such things as compressed air, natural gas, hydraulic oil, pyrotechnics, etc. Other manufacturers know a good thing when they see one and have jumped on the bandwagon, so it appears that MSC is going to be another popular MIDI extension.

• General MIDI: Roland and Passport worked hard to get this one across, because it will be difficult for consumer/multimedia MIDI to take off unless people composing MIDI 'clip music' have some assurance about what the sequence will be playing back through. Among other things. General MIDI (Level 1) correlates specific sounds to specific program numbers, creates a standard drum note map, and defines a GM instrument as having at least 24 dynamically allocatable voices, 16 MIDI channel response, drum/percussion sounds on channel 10, and at least 128 programs.

And that's still not all. Some of the other recently-adopted or about-to-be-adopted goodies include:

• All Sound Off: Unlike All Notes Off, this command also sets envelopes to 0 as rapidly as possible.

• Sound Controllers: Controllers 70-79 are defined as 'sound controllers' that affect the overall timbre of a sound. There are already five recommended defaults: 70 creates sound variations, 71 changes harmonic content, 72 edits release time, 73 attack time, and 74 brightness.

• Legato Footswitch: This turns legato mono response on or off, which has several uses but would be of particular interest to guitar synthesists who want to rapidly switch a sound module to match mono or poly mode string output.

• Bar Marker and Time Signature: This Universal Real Time SysEx message means that the next clock received indicates a new bar. The time signature message can either take effect with the next clock or next bar marker.

• Tuning Standard: Not only does this define alternate tuning tables that spell out the exact pitches for each MIDI note, but also allows for on-the-fly retuning of individual notes to allow for simplified modulation without having to load new tables.

• File Dump: The biggest problem with Standard MIDI Files is that they work when transferring files via disk or modem, but can't be transmitted over the MIDI line. This extension fixes that problem by providing a way to get SMFs, as well as other MIDI file types, into a format that can travel down the MIDI cable. Finally, we can get sequences from one place to another without having to play them in real time and record them!

END OF THE LINE?

Is this the end of the line? Absolutely not — this is just the tip of the iceberg, and we might have additions like SMDI (SCSI Musical Data Interchange, for high-speed SCSI sample transfers) before too long.

MIDI's vitality is nothing short of remarkable in today's fast-paced world; it seems only fitting that musicians, who are often known for not fitting in with the 'real world,' went ahead and created their own world standard that works just fine. If only the rest of the electronics industry would heed this lesson!

Based in California, CRAIG ANDERTON is the author of several books on musical electronics, including Power Sequencing With Master Tracks Pro/Pro4 (available from SOS Bookshop (Contact Details)). His samples and patches have been used in products from Emu, Ensoniq, Northstar, OMI, Peavey, Prosonus and Yamaha.