Music is an important diversion for the novelist Iain Banks, but without his Freestyle software and Midi interface he wouldn't be able to translate the tunes in his head into real songs
Freestyle is basically a music processing program. Using it is a bit like word processing, but with notes instead of words. My Power Mac computer runs the Freestyle software, and a Midi interface called Studio 4 lets the computer talk to all the other bits and pieces like the keyboards and drum machine. Then it goes into a mixer. In the same way you alter the position of the words when you use a word processor, you can change musical notes. If I hit the wrong note, it can be corrected on the computer screen.

On the left-hand side of the screen is an up-ended keyboard with all the piano keys running up and down the screen. And on the other side there is something like a big piece of paper stretching out, with coloured blobs for different instruments. These instruments can be built up from one voice to an entire orchestra.

The beauty of the whole system is that it's just a question of having headphones linked up to the mixing desk; there is no need for sound proofing, for example. It sits as part of my desk, a small rack by my computer. I have got the same set up for my writing - it's all quite handy from that point of view.

The program is designed to be very easy to use. It is quite powerful, and very intuitive. For example, the different layers for editing lend themselves to a verse, chorus, middle eights and solos approach, and that means you can put verse and chorus together very easily.

The whole song can come together very simply. It's similar to cut and paste in word processing. It makes you a one-man orchestra. You find yourself doing stuff that you could only imagine before.

Without this equipment I don't know if I would be making music at all. I hadn't wanted to be involved with a band because I am a control freak really. I don't think I would take other people's input very well. But I like making music. I hear a tune in my head and I think, it's mine, I made it up. It's like having an original idea for a book. And it's great to be able to do it now, after all this time of hearing the tunes in my head.

I have done various things by myself, but the main thing I am working on is the music for the film version of Espedair Street with a friend of mine called Gary Lloyd, who is a professional composer.

First of all I listened to some tunes I had recorded on old tapes back in 1974, and then I played them into the software and tinkered around until they sounded reasonably comprehensible, like real music - with real notes, anyway. Now Gary has the music on a compatible disk - he has an Atari system, it's ancient but a lot of musicians still use them - and will turn these warblings into proper music. Gary is much more adept at music programming, attaching various sounds so they sound like proper songs. Then we'll get a band together and do a live recording.

It's not difficult to use this program, you just need to have an original idea, or a tune that's in your head. Once you've got that you are off and running. But you need that originally, otherwise you are creating something that somebody else has already done.

The beauty of a system like this is that you can use any sounds. You listen and audition them until you find the one you want. A good system just lets you do the basics and if you want you can delve into something more complicated. I am slowly learning about the more complicated elements, but I need to spend a lot more time on it. The program comes with loads of manuals. They are pretty good, though, and take you through all the basic steps like a tutorial.

Freestyle is written for budding musicians, and is perfectly good for proper musicians as well. But it's probably aimed at someone like me who wants something that is fairly intuitive, and doesn't want to have to refer to the manual a lot.

I buy a fair amount of gadgets. But I do have to stop myself sometimes. For example, I had been thinking for quite a while that I would like to have a GPS, a handheld global positioning system, but I could never come up with a good excuse to buy one - I don't go hill walking enough. Then a friend bought me one.

But yes, I have pocket tape recorders, pocket radios, mini televisions, all that sort of stuff. I have decided that as far as computer games go, I am an addictive personality. I had to give away Civilisation 2 because I would play for days on end, to the extent that when I went to sleep I could still see the screen.

We decided that it might be the case with the Internet as well. I think you can become addicted to the whole thing. I could be wrong, but I am cautious now.

`The Business' by Iain Banks is published by Little Brown, price pounds 16.99