Rob Hubbard is Britain's top computer music programmer, creating sounds and melodies for video games. His work is a constant struggle to coax impressive sounds out of limiting hardware, and his success story is something every modern musician could learn from.

Suppose I offered you a sizeable amount of money to provide the electronic soundtrack for a project of mine, due to appear on television screens across the country in a couple of months. How much equipment do you think you'd need?

A polysynth or two, certainly, and a drum machine. An old-fashioned monosynth would probably come in handy for bass and lead, and a sampler would be nice for 'natural'sounds.

Then, to control everything, you could use a Commodore 64 running a MIDI sequencer program like the Steinberg reviewed in E&MM last month. Of course, you'd also need some recording gear (or a studio that has some), so that you could devote all your ideas to tape, and add just the right amount of carefully tailored digital reverb at various points.

But there's a problem. You see, on this project, you aren't allowed to use any effects. Or tape recorders, or drum machines, or keyboards. What does that leave you with? SID, that's what. For the uninitiated, SID stands for Sound Interface Device. It's built into every Commodore 64 (easily the world's biggest-selling computer) ever produced, and as you may have guessed by now, the soundtrack I've been talking about is for a C64 video game.

Writing music for the C64 is one of the easiest, certainly one of the quickest, ways of driving yourself insane. Sound has always been the poor relation of graphics in the computer game world, proof that humans are more interested in what they can see than in what they can hear (this explains the success of Five Star). Playing second fiddle to the graphics means you get allocated only a tiny share of the computer's memory, typically between 4K and 6K. Not only do you have to fit your tune into that space, you also have to find room to define all your sounds — not just for the music, but also for the game-activated sound effects.

Worse than this, everything you come up with has to be turned into sonic reality by SID. The SID chip is a (very) primitive analogue device. It has three sound channels, each with its own volume ADSR, and can produce one of four waveforms. There's no LFO, though it is possible to steal one of the three oscillators and use it as one. You can also sync two channels or ring-modulate one with the other, which helps to liven things up a bit. Finally, there's a three-state filter which would doubtless come in very handy if only you were allowed to use it. Trouble is, the filters on old 64s are calibrated so differently from those on newer machines, that a piece of filter-inspired commercial software might sound great on one person's 64, but utterly appalling on another's.

With these limitations to deal with, you might expect the final result to consist of a very short tune played repeatedly by thin, uninteresting bleepy sounds (a bit like Five Star, in fact). And that's exactly what most game soundtracks did sound like, until Rob Hubbard came on the scene.

Rob Hubbard is more than just the top music programmer for the Commodore 64. He just about invented the entire profession. When you listen to one of his soundtracks, you're convinced he's managed to sneak in a Casio CZ, an Akai AX80, an OSCar and a digital drum machine into your computer while you were reading 'War and Peace' waiting for the 64 disk drive to load the program. Somehow, Hubbard manages to coax powerful bass sounds, pseudo-digital DX-type voices, a large variety of hefty lead sounds, and some pretty decent Simmons drum imitations out of SID. And impressive as these sounds might be in isolation, the real shock comes from hearing a bassline, two melody parts, a bass-and-snare rhythm track and various percussion effects, all running at once in a compelling piece of music that's full of variations, and lasts quite a few minutes before it repeats.

Clearly, Hubbard is a major talent, a programmer capable of conjuring whole orchestras of sound from even the humblest of sources. And unusually for a man so obviously gifted, he is keen to share his programming secrets.

'The basic way that it works', he says, 'is that I have in software what you'd call programmable patches, and the "sequencer" part of the memory flips between these. This means that I can use a channel to play a note in a bassline with one sound and then, a semiquaver later, flip it over to use in a percussion part.

Things are carefully written so that although there seems to be a lot of things happening at once, I never need more than three notes on any given beat.'

That's rather like being told by an expert juggler that it's easy to keep six balls at once: you just arrange it so that you only ever have to catch two at any given moment. But although this goes some way toward explaining how Hubbard gets so much out of three channels, it does nothing to clarify the sounds themselves.

'That's all down to software. I have an interpreter program whose job it is to take my music data and drive the chip. This program contains routines that perform various software tricks. For instance, I have routines that give vibrato without having to use another channel as a modulation oscillator. I just generate the LFO in software, and it can have absolutely any waveform I choose to program into it.'

Some of Hubbard's other software routines join forces to produce even more unlikely effects. On one game, a delayed vibrato routine merges with another which gives pitch bend: the result is a solo that could almost be generated by a Minimoog. And the man's software tricks don't end there, either.

'Controlling all the aspects of sound from software, I can do tricks on the Commodore that you can't do on a synth. For instance, I can start a note off with a channel set to white noise, and then switch very rapidly to another waveform, or indeed change any of the other parameters while a note is running.'

Hubbard also makes much use of the SID chip's unusual ability (thanks to its 16-bit resolution) to play notes that lie between the black and white notes of a normal keyboard (to have the same resolution on a piano, you'd have to build a keyboard over 65,000 notes long). This means you can do some extremely odd things to pitch whenever the fancy takes you, and provides Hubbard with an almost limitless range of sound effects and other-worldly electronic voices.

Thus Rob Hubbard's extraordinary sounds are a combination of two things: his extensive library of clever routines, and the fact that his 'sequencer' has direct control over the astonished SID. The first merely compensates for hardware problems (and we all get those now and again), but the second opens up whole new horizons of analogue synthesis.

'If you had that degree of software control on something like a Prophet 5 or a Roland JX8P', the programmer asserts, 'you'd be able to generate some amazing sounds.'

Yet today's synth market isn't exactly bursting with instruments offering that degree of control, though Oberheim's Matrix Modulation system (as used on the Matrix 6 poly and its forthcoming modular derivative) comes close. Hubbard, meanwhile, has a vision of MIDI sequencers controlling synth parameters through System Exclusive data in real time, forming music systems that open up genuinely new programming paths. At the moment, that vision seems a little way off: the average MIDI synth and sequencer are like two people signalling clumsily to each other in opto-isolated morse code, but never actually meeting.

Evidently, Hubbard would like to see a return to the sort of programming fun that could be had in the heady, pre-MIDI days of using synthesisers. The days when, providing you were handy with a soldering iron, you could connect anything up to anything with CV and gate leads, not just to play one instrument from another, but to get each machine to feed off the other to produce sounds that couldn't be generated by either device in isolation. It was at that time that Hubbard served his apprenticeship in getting the best out of limited resources, with a Korg 800DV monosynth (his first, which he still has), a Multimoog, and a rhythm section comprising Roland Drumatix, Bassline and MC202 Microcomposer.

'It was an amazingly creative time. It was great fun, linking everything up, running everything off triggers. I used to build loads of E&MM modules, especially the percussive ones. The best project was one that had six little drum pads on it, which sounded like a set of electronic bongoes. I've lent that to a mate of mine, and somebody else asked if they could borrow it last week — so it still has its appeal, even today.'

Hubbard now gigs regularly with a club band using a DX7 (NB — a DX7 is a large lump of metal and plastic that follows you wherever you go, and is on television more often than Terry Wogan), continuing a tradition of playing music that started with childhood music lessons. He dropped out of University to play keyboards in a band, but when they didn't make it, he went to music college instead, later working with long-time collaborator Steve Daggett to produce a half-hour electronic musical called 'Work', entirely on four-track. As I write this, Tyne Tees Television are working on a cut-down version of the piece.

But what led Hubbard to add a Commodore 64 to his equipment list?

'Strangely enough, it was E&MM that made me get one. It was when the computing side of the magazine was starting to expand, and the 64 looked like the best thing to get.'

People who buy 64s either give up programming or learn machine code, as the BASIC is not only slow (all BASICS are slow) but also gives you almost no access to the machine's music. Luckily, Hubbard took to coding like a journalist to alcohol, and was soon working on a serious program.

'At the time, E&MM was showing all this highfaluting educational software that was coming out of America for the Apple, and machines like it. I thought I could write something like that for the 64, and be the first in this country to do it. So I wrote this piece of educational music software, all notes on a stave, "find the mistake", and that sort of thing. But with Britain being ten years behind the States, not in its brains but in its attitudes, I couldn't find anyone who was interested in marketing it.'

Not discouraged, Hubbard hit upon the idea of becoming a specialist music programmer, providing the music for other people's games. He set to work developing his unique 'system', and, after a lot of mailouts, telephone calls, and general hassling, finally managed to get some work programming.

His first assignment was to produce the music for a game called 'Confuzion'. The sounds were by no means Hubbard's best, but magazine critics were bowled over by them, gave the game rave reviews, and launched the programmer as a successful freelance.

These days, he's keeping an eye out for new machines with greater music potential. He was especially annoyed when the Atari ST, a computer with so much to offer in terms of speed, memory, resolution and even MIDI, turned out to have the same sound chip as the Amstrad 464.

'It's a poxy chip, that', he complains. 'It's only got two waveforms: square wave and white noise. Also, it hasn't got any ADSRs in hardware, and the resolution on pitch is only 12-bit, so there are tuning problems.

'The new Commodore Amiga seems to me to be the only computer which has sound facilities that are a step forward from what I'm using now, rather than a step back.'

So Hubbard is hoping to get his hands on an Amiga as soon as possible, and judging by what he's managed to squeeze out of SID, he and Portia — the Amiga's rather more impressive sound chip — should make beautiful music together.

In the meantime, Hubbard is making a comfortable living from writing on the C64. If you have one, you can find some of his most impressive work on two games: 'Crazy Comets' on Martech (very New Order, this), and 'Commando' on Elite. Although Hubbard didn't write the melodies on 'Commando' as it was a conversion from an arcade machine, he has done an astonishingly good job of converting the original music, which was written for a six-voice system.

Thanks to performances like these, software houses now call him, and his work continues to get rave reviews. That's quite an achievement given that the computer press is almost as fickle as music magazines, but not surprising when you consider that, whatever else he might do, Rob Hubbard rarely puts sonic pyrotechnics before good music. He's not in the business of making people say: 'My God, is that really coming out of my 64?'.

Hubbard is really a musician first, a programmer second. He's a composer who's been forced to develop incredible programming skills in order to drag his music, kicking and screaming, from limited hardware. And in that respect, of course, he's no different from any other musician trying to get to grips with modern technology.