There can be few people who have made a greater impact on the direction of modern day music than Dr R A Moog. It may be argued that the synthesiser was an inevitable development, and that it was only a matter of time before someone produced a similar box of tricks. But it was Moog who actually formed various electronic circuits into a practical musical instrument.

Moog's first encounter with electronics was as a youngster in New York City. His father was an electrical engineer and had taught him how to use a soldering iron before he was ten. As a school project Moog had chosen to build a Theremin, an electronic instrument that emitted a whining note, the pitch of which was changed by moving your hands over its antennae. He continued to make use of Theremins at college, where he sold them in kit form. This was around 1960 and the sales of the Theremin kits were amounting to almost $50 000 per annum.

In 1964 Moog started up a partnership with Herb Deutsch, a previous Theremin customer, to develop a voltage controlled oscillator, a voltage controlled amplifier, a keyboard controller, and the now-famous Moog voltage controlled filter. A small group of composers showed an interest in these devices and ordered several modules from Moog and Deutsch, and soon several institutions were using their equipment. At that time (since most modules were custom designs) everything was hand wired; no printed circuit boards were used.

A couple of years elapsed and then a certain Walter Sear, who had sold Moog's Theremins, saw a market for the synthesiser in the advertising industry. In a very short time many commercials were using the Moog devices on their soundtracks. The late Paul Beaver (of Beaver and Krause) had a musical instrument rental company at that time and began selling the Moog equipment to many studio musicians — the demand for the new instruments was growing. However, it was not until Switched on Bach hit America that things really started to happen.

Walter Carlos, an engineer at Gotham Recording in New York City, had put together an 8-track studio from surplus Ampex spares. He had shown great interest in synthesisers and, having purchased one of Moog's machines in 1966, began recording Switched on Bach. With the exception of one track, the record consisted of traditional Bach compositions performed entirely on Moog synthesiser. Carlos eventually got Columbia to release the album and in 1968 it became the greatest selling 'classical' record of all time.

During 1969 countless Moog records came out, trying to capitalise on Carlos' success, though of course, no one could match it. Moog synthesisers, however, were as successful as Switched on Bach; everyone wanted Moog equipment in their studio. But the major drawback with Moog's synthesisers was that they weren't 'live' instruments. Moog was inundated with requests to design a synthesiser that could be taken on stage — Keith Emerson, then with The Nice, had been the first musician to take a Moog system on stage with him, but he had to rely on his friend Mike Vickers crouching down beside the instrument to reprogramme it after every number!

So Moog developed preset boxes to make fast changes possible, but there was a big demand for a smaller unit with a fast, easy to use set of controls. Jim Scott's aid was then solicited with the aim of producing a new performance synthesiser and finally, in 1971, after consulting scores of musicians and engineers, the Minimoog was revealed at the AES Convention in New York. The instrument was an amazing success; the main reason being that it was a musical instrument, not just an electronic box of tricks. Demand for the Minimoog grew and grew and Moog Inc had to move from their small Trumansburg factory. They merged with Musonics, a company in Williamsville, NY who had also been active in the electronic music industry, and who had the space, equipment and staff to help Moog push their output up to 300 Minimoogs a month. The Minimoog had become the synthesiser — it was and still is the standard to which all other performance synthesisers are compared.

As the Minimoog became established so Moog was inundated with requests to design a polyphonic synthesiser — the Minimoog, of course, being monophonic. So in 1972 Dr David Luce, already known for his electro-acoustic work, joined Moog with a three year brief to design a polyphonic synthesiser.

The prototype system first considered was known as the Constellation, and it consisted of three instruments: the Lyra (a monophonic synthesiser), the Apollo (polyphonic), and the Taurus (a pedal synthesiser — now available as a product in its own right). However this system proved to be unsuitable for marketing mainly, I would imagine, for economic reasons.

The major problem associated with producing a polyphonic machine was the large number of components required; in effect there had to be a synthesiser on each note. To get over this Luce developed a custom integrated circuit (IC) the size of a thumb-nail, containing two wave shapers, a voltage controlled filter, two contour generators, and a double voltage controlled amplifier. This IC came to be known as 'the polyphonic chip,' and greatly eased the task of getting the instrument down to a manageable size. After spending years and a small fortune perfecting the sounds, ergonomics and cosmetics of the instrument, Moog finally revealed the Polymoog to an eager world. Although the Polymoog has since failed to capture the control of the polyphonic market it has proved to be a popular instrument, especially in the studio environment.

While work was being carried out on the Polymoog, Jim Scott had been aiming at the lower end of the market and in 1975, after Moog had merged with the giant musical instrument distributors Norlin, the Micromoog was introduced at the NAMM trade show. It too became extremely popular: it was small, relatively cheap and still had that famous Moog sound.

Dr Moog, now Director of Research for Norlin Music, has recently turned his talents towards amplifiers, producing the SynAmp (the ultimate synthesiser and keyboard amplification system), and the Lab series of bass and guitar amplifiers. However, the name Moog will always be associated with what is the most important development in recent musical history — the electronic music synthesiser.

It would seem sensible to give a brief overview of the Moog production instruments. These fall into two basic categories: performance synthesisers and studio synthesiser systems. These are only guideline headings as studio systems have been successfully taken on the road (viz Keith Emerson's modular Moog), and performance instruments are commonly found on studio recordings.

The Performance Moog synthesisers are as follows: The Minimoog is without doubt one of the most popular synthesisers ever. The instrument's basic facilities include three voltage controlled oscillators (VCOs), one of which can be used for filter or oscillator modulation; a voltage controlled filter (VCF); two attack, decay, sustain (ADS) envelope generators; one voltage controlled amplifier (VCA); and a noise generator. The instrument is very easy to control, and has the two famous Moog wheels, one for pitch bend and the other for amount of modulation. There is a 3½ octave F to C keyboard housed in a sturdy wooden case, with hinged front panel — this feature makes the Minimoog instantly recognisable. But the best thing about the instrument is the sound; very full and rich, it leaves most synthesisers standing. An excellent machine that won't be bettered for some years to come.

The Micromoog is a smaller instrument than the Minimoog (yes, really!), having only one VCO, less comprehensive envelope generators and a ribbon controller instead of a pitchbend wheel (I personally find the ribbon controller more difficult to use). To overcome the thinner sound resulting from only oscillator the Minimoog does have suboctave doubling and also pulse width modulation which give the instrument a very pleasing sound. It is light (20lb) and well priced; I would recommend this instrument to someone taking their first steps into the synthesiser field.

The Minitmoog was Moog's answer to the preset synthesiser, taking the most popular synthesiser voices and putting them into preset form. The instrument has two tone oscillators, a touch sensitive keyboard and a bank of twelve preset voices with nine function selectors and six effect controls used to modify any of the presets. There are, unfortunately, no pitch or modulation wheels and, though this is quite a good instrument, I feel Moog are at their best building continually variable instruments — the Minitmoog has, in fact, been discontinued from the current catalogue.

The Sonic VI is quite an old Moog model and is also one of my favourites. It is built into a moulded ABS transit case, and can not only do most of the things a Minimoog can do (with the exception of the one envelope which is very restricting), but also provide ring modulation and two very comprehensive modulation oscillators. The Sonic VI does, however, drift out of tune quite easily and also is not very easy to use live. This instrument is also discontinued from the current catalogue.

Anyone who has seen Genesis live will realise the power of the Taurus bass pedals. A 13-note pedalboard drives a two-oscillator synthesiser, with three preset voices and a programmable voice of your own, easily selected by foot switches, and four other fast switches to modify the presets. The main criticisms of these pedals are: 1 The ridiculously designed plastic cover over the programming controls which always falls off; 2 The fact that the foot sliders and footswitches are mounted directly on to the one main printed circuit board, and if the instrument receives too great a blow, the board will crack; 3 It is quite an expensive instrument. However, it is a great machine that can be used by guitarists, drummers, vocalists, even dancers; or of course it can be hidden beneath a mountain of keyboards.

The Polymoog is unlike most so-called polyphonic synthesisers in that you can play all the notes at the same time. It has a long 6-octave keyboard and over 100 controls within four inches of that keyboard. It would take too long to describe the instrument fully, but it has most of the usual synthesiser functions associated with each note. There are also eight preset sounds (imitative), all of which can be modified — the best is the string preset which can sound beautiful both live and when recorded. The Polymoog has had its problems and, even though it is extremely well designed and laid out, there have been reliability problems with some instruments, most notably with the earlier production models.

There are three basic studio systems in current production, the System 15, System 35, and System 55, though Moog will supply modules separately: your system can be customised to your requirements. All three systems rely on a jack cord patching and, mostly for that reason, are unsuitable for live work. They are however really professional machines and are built to a very high standard. Detailed descriptions of these instruments would be somewhat space consuming, but to sum it up, there's not much you can't do with the System 55 (musically, that is).

Moog also provide a wide range of accessories, including ribbon controllers, sample-and-hold modules, footswitches, percussion controllers, and footpedal controllers. These are quite expensive items but they do enhance the particular synthesiser with which they are employed. Moog synthesisers use the now common 1 volt/octave system of voltage control, so these can be used to interface with other makes of synthesisers, sequencers, programmers et al. However, Moog use a unique triggering system that uses the shorting together of two terminals to trigger envelope generators. This should be borne in mind when interfacing with other devices.

There can be little doubt that Moog means quality. I am more impressed with their products than those of almost any other manufacturer, though they are going to have their work cut out competing with some of the new Japanese products recently announced, most notably the new Yamaha range. Moog do, however, have two new products emerging on to the market, the Multimoog (a cross between a Minimoog and a Micromoog) and the Polymoog Keyboard (an almost totally preset Polymoog), which I will be looking at a lot more closely before long. But I can see no musical instrument whatsoever emerging in the next 20 years that will make as much impact on music as Moog's synthesisers have over the past decade. I could be wrong — but I don't think so.

Dave Crombie is resident electronic design engineer at Rod Argent's professional keyboard store in central London.