Why MIDI?

When synthesizers were first produced no-one imagined that you might want to interface products of two different brands together. A sort of standard did however evolve; not so much by mutual agreement as by manufacturers copying one another. When one-volt-per-octave keyboard calibration almost became the norm there were still a variety of triggering differences, the most notable being the Moog Switch Trigger as opposed to other people's Voltage Trigger. Another problem with voltage control is that two leads are needed for each voice: one for pitch information and the other for trigger and gate. This was no great drawback when most synthesizers were monophonic, but some recent set-ups have looked as if they needed a healthy helping of Bolognais sauce.

The most obvious answer was to develop a system where many lines could have been run in parallel using something like a Centronics plug — a standard fitting in the computer industry. But these connections are expensive, complicated and delicate — they could perhaps give rise to some embarrassing on-stage soldering.

Luckily, synthesizer manufacturers decided it would be in everybody's interests to cooperate and develop the best possible system, making the technical information freely available to all so that it could become truly universal. This has resulted in the development of MIDI (Musical Instrument Digital Interface) which has some positive advantages over previous systems.

With a voltage control system both leads for each voice are fully occupied with information whenever a note is being played. Modern synthesizers with MIDI have digital keying which means that once the synthesizer has been told to play a particular note, which takes a tiny fraction of a second, the note will continue to play until it is told to stop by the removal of finger from key. This leaves the connecting lead completely free during the intervening period so that all sorts of other information can be passed down the line. For example, another note can be told to play — in fact the synthesizer's full polyphonic capability can be utilised as the time taken to pass information is so short that it cannot be detected by the human ear.

Until this stage the only advantage over voltage controlled systems is the neatness of using one lead serially. But once we have told a chord to play, the line is still free to pass other information. Touch sensitive dynamics, patch select, Hold and Bender messages can now be transferred to the other instrument and the system is open for future development of other parameters that may be exclusive to a particular manufacturer or common to all.

Roland are so determined to make MIDI work as a universal standard that they are even developing interfaces that will make pre-MIDI products compatible with the system. It really is the most exciting development in synthesis since voltage control — the first computer-compatible obsolescence-proof interface system in the world.

Alan Townsend is Head of Product Training and Education, Roland UK

Midi at Frankfurt

MIDI will be the theme of the Roland exhibition at Frankfurt, with a variety of new additions to the Roland MIDI system.

MIDI keyboards will form the centrepiece. The JX-3P and the Jupiter 6 are both fitted with the bus as standard, dramatically increasing their potential within an electronic music system and rendering them effectively 'future-proof; because the system will be continually updated with new technology, individual products won't become obsolete.

The HP-300 and HP-400 Home Pianos are MIDI equipped and communicate with a purpose-built MIDI recording unit; the PR-890. This combination not only allows the recorder to re-play a piece through the piano without any degradation, but also exploits MIDI's ability to transmit information on dynamics so that all nuances of a touch-sensitive keyboard are preserved. Being a digital recorder it can of course allow tempo to be altered without affecting pitch, tape dump is possible and re-play can also be through a MIDI synth such as the JX-3P or the JP-6 — using all the sound capabilities that these instruments offer. The PB-300 Rhythm Plus is also MIDI-linked to any MIDI keyboard and will give a complete Chord/Arpeggio/Bass/Rhythm accompaniment with fills and a 'Nuance' feature which allows the Rhythm Plus to vary in volume according to how hard the left hand piano keys are hit.

All Roland's MIDI keyboards form part of a system but none more so than the new MKB1000 Mother Keyboard. This new product might be compared with the move in HiFi from gramophones to separates. It is not a complete system but an 88-note touch sensitive keyboard module designed to interface with other component modules via the MIDI bus. Already a piano and synth module have been produced, but the MKB-1000 will soon be the heart of a complete MIDI based electronic music system using 19" rack mounted 'separates'. This may be the stage or studio system to out-perform the time-honoured Roland 100M at a significantly lower price.

Having established a full range of MIDI polyphonic keyboards the Roland R&D teams turned their attention to providing micro composer systems to match. The most important such product is the MSQ-700 which is billed as a Digital Keyboard Recorder but which has microcomposition capabilities comparable with the MC-4B. This unit will memorize all the MIDI functions including dynamics, can handle several keyboards and can be programmed in step or real time. It is also remarkably simple to use and will work with MIDI DCB equipment. At £850 the MSQ will be the MIDI DCB microcomposer for the next few years. For those with DCB instruments a less expensive 'keyboard recorder' is the JSQ-60.

A dramatic 'first' at the Roland stand for this year's Frankfurt show is a brand new MIDI guitar synth — a product which is in its own right many times more versatile than any previous guitar synth, and which will also link into the MIDI network. So for the first time ever, you can play a keyboard with a guitar — retaining all the character of a guitar technique but using the sound facilities of synths like the JX-3P or the Jupiter 6. Or, with the MD-8 interface, the Juno 60 and Jupiter 8. The standard synth module is programmable using the PG-200 — the programming module supplied for the JX-3P. The guitar controller is perhaps the most radical new guitar design ever — Steinbergers included — but full details will be published in the next Roland Newslink. Suffice it to say that as electronic music becomes synonymous with MIDI links, guitarists won't be left out of the action. The new guitar controller and guitar controller will drive any existing Roland guitar synth module and new module can be driven by an existing GR controller.

And as the guitar has gone MIDI, so have the drums. True to the Roland tradition of bringing out at least one really devastating rhythm box every year, Frankfurt sees the introduction of two. One of these, the TR909, is equipped with the MIDI interface — the first rhythm box ever to go MIDI.

The TR-909 can be controlled by the MSQ-700, the GR-700 Guitar synth or the MIDI keyboards — creating the dramatic opportunity for the keyboard or guitar player to take a drum solo.

Some Roland products, notably the Juno 60 and the JP-8, do still have the less versatile DCB interface. But for the first time, these units can be quickly and conveniently linked with the MIDI system, opening up all the advantages of the computer-link to instruments without the MIDI socket.

The key to this new capability is the MD-8 MIDI/DCB interface. This circuit box is the 'bridge' between MIDI equipment and DCB equipment. It can for example connect one keyboard to another so that a DCB instrument such as the Juno 60 can 'drive' a MIDI unit like the JX-3P. There is also the capability of exchanging patch information between, say, the JP-8 and the JP-6. The interface should also allow DCB instruments to be connected into any system driven by the new Mother Keyboard. It means that sequencers/microcomposers designed for MIDI link such as the PR-800 can drive non-MIDI instruments, for example a Juno 60. The MD-8 also has a channel selector which can select communication on any MIDI channel from one to 16. This is important since it is possible to run more than one instrument from the same MIDI connection by allocating them to different channels.

Designed specifically to exploit this facility of MIDI for multiple control set-ups, the MM4 MIDI thru box does for MIDI what Roland's J-5 jack junction does for conventional wiring. Using it you can, for example, drive four MIDI synthesizers with a fifth MIDI synthesizer or the new Mother Keyboard. The unit works off a DC 9V power source (with accessory mains adaptor) and has 'data indicators' on each channel to indicate that the MIDI data is flowing through.

MIDI is going to be the theme of this year's Roland stand at the Frankfurt Fair, and the range of new products dramatically expands the MIDI system. More MIDI devices will follow later in 1984, not replacing but expanding the potential of existing lines. MIDI is a versatile system that is also competitive in price and the end result will be that full polyphonic electronic music systems will, during the coming year, be a practical proposition for more electronic and computer musicians than ever before.