They took MARRS to court, they took several acts to the top ten, and they're preparing to fight the law on sampling. These men like a challenge. Stock, Aitken and Waterman are hit makers. John Morrish ducks the guided missile in reception, and asks how. And occasionally why.

Stock Aitken and Waterman: it sounds like a firm of solicitors. In fact, they're the hottest production team of our day, but that doesn't prevent them having their own share of dealings with the law.

Not by choice: it's just one of the perils of success that people want to imitate you, impersonate you and steal your work.

Mike Stock: "There is a precedent to be set in the music industry, and it's to do with sampling. Until the law has a test case I think we are all on extremely dangerous ground. 'Pump Up The Volume' [by MARRS] was sampled from as many as ten or 12 of other people's records and used as the fundamental ingredient of their song. In the case of our record 'Roadblock', it was still in the charts. It's not like sampling James Brown from God knows then, this is a record that's current and they're using it to gain momentum and appeal for their own single. Their record is basically a bass line and drum pattern [he hums it] and the rest of it is all samples of other people's work..."

Stock: "You're not just nicking an idea, but the performance, the performers, the musicians. Nobody else is getting paid for 'Pump Up The Volume'. We've got a girl called Coral Gordon who sang that "Way-ay-ay-ay-ay-ay-road-block. She got one fee for that, but now 'Pump Up The Volume' is selling records using her singing and that's not fair."

So, later next year a judge who has never heard of Bruce Springsteen will be deciding the rights and wrongs of the case: a case brought not simply by Stock Aitken and Waterman's publishers, but by the heavy mob, the BPI and the MCPS, in a bid to draw a line between "creative" use of sampling (to which SAW themselves are happy to plead guilty) and old fashioned theft.

But it doesn't stop there.

Stock: "We've got all sorts of problems. Everybody is claiming we're having something to do with them." Aitken: "We've had two labels changed this week because we were credited with producing and mixing the records, when we hadn't." Stock: "We have to protect ourselves. At the moment we've only got two records out, but it appears like we've got 60. That's prejudicial to us, because we don't want the radio saying, 'Oh, not another Stock Aitken and Waterman record'."

What about Waterman, by the way? The sleeve of the Mel & Kim album credits him with playing "cash register". Stock and Aitken go along with that. They produce the music, it seems, and he produces the money. But he's a former club DJ who is always welcome to drop into the studio and apply what they call his "Woolworth's Ears" to the results of their labours.

Today Stock and Aitken are making more hit records, as both writers and producers, than anyone since the heyday of Chapman and Chinn. Take a look at the list of clients: Bananarama, Mel & Kim, Pepsi & Shirlie, S'manfa Fox, Princess, Dead or Alive, Rick Astley, Sinitta and more. What all these acts have in common is that they have a saleable look: none of them is Aretha Franklin, that's for sure.

The artistic input comes very largely from Stock and Aitken: but the extent to which these guys actually make the finished product is extraordinary, even for today, when one man and his cheque book can perform musical miracles. Three years ago, no-one had heard of either of them. Now they are learning to cope with the pressure of success.

Stock: "We could be working on anything up to 20 songs at any one moment. What we actually do is to go in the studio at 11.00 in the morning and having decided what we're doing today, say we're doing a Rick Astley song..."

Aitken: "... We have the audacity to sit there..."

Stock: "... at a keyboard and write it at that moment. We talk about it. Not that we over-intellectualise or analyse, but we come up with an ethos of what we're doing. We say 'Rick is this, what's going to sit comfortably on Rick, Rick can sing this, he looks like this'.

"We're bespoke tailors in a way. We know what Rick is and we know where his appeal is. A lot of people criticise us — we're over-facile, it's all superficial rubbish. It's not, it's just a well-designed suit of clothes that fits people, and people who go out and pay their money over the counter are proving that for us.

"Say it's Sinitta. We know we've got to follow up 'So Macho' and 'Toyboy', so there's no point in giving her a really serious meaningful song. We're talking about throwaway pop here, for people to dance to, to sing to, for kids to like.

"So we sit down, we've gone through all that in our minds, we might begin with a title. We start at the keyboard with an idea in our heads about what we're going to say. We'll get a drum loop up. For example, with Sinitta we know it's going to be a Eurobeat, four bass drums on the floor to the bar, a few shifties in that, ticky-ticky-tick, ticky-ticky-tick, sixteens on the high-hat, a sixteens feel."

Aitken: "We work out a system of chords we can feel comfortable with, what we can write the verse and the melody around."

Stock: "The verse is the last thing we think about. It's the chorus that you want for a pop song. We've got a system of chords and a melody idea that fits the lyrical content, and as long as we know we've got that, we would put the guide chords down and go on to the bass. In Sinitta's case we'd be going for a Eurobass. We know what that means, we know how to program it, and in the case of the bass Matt would jump onto the bass keyboard and we'd sequence it into our Linn 9000.

"We're very keen on structure. We like to have an introduction, which in most cases takes the form of the chorus chords, and then you have the verse, then a bridge, then a chorus, then another verse, bridge, chorus, then you have the middle eight and so on. It'll all be finished by three minutes, and that's what we aim to do.

"The skill in songwriting is to make the changes between the sections imperceptible so that the melody just appears to approach these things then all of a sudden you're in the chorus... lifted into the chorus somehow. It wouldn't be possible in a lot of our songs for people to say, well, this is definitely the bridge and this is definitely the verse, because you like to be able to disguise what you're doing.

"In a lot of our songs, the way we go through chord changes means that a lot of people are unaware that there are a lot of chords in there. It sounds simple but it's not. Our choruses are very often a tone higher than our verses, in a totally different key."

Aitken: "We had this problem with 'Say I'm Your Number One' [a big hit for Princess] which we'd written at Mike's place. We had some verse ideas. Then we did a demo version of it with another singer and to our chagrin we discovered that it actually dropped into the chorus.

"What we ended up doing was placing the chorus a minor third above the verse, a very unusual interval. Then it goes down again at the end, and at the middle eight, all by minor third degrees, which is very unusual."

Stock and Aitken have some advice for the novice songwriter.

Aitken: "Get your Beatles song book out."

Stock: "To get your experience, you have to write and write and write and accept the comments that people make. If you have a talent and ability, get your structure right. Is it understandable to people? Get the point over and stick to your point. Don't deal with all the world's problems, deal with one thing. Say 'I love you' in a way that sounds a bit different. Or say 'Let's have a good time', or 'I'm sorry that I hurt you', or 'I wish you would come back to me', anything that's got a human relationship or appeal in it. Say it in an original way, get your structure right, and if you've got talent and ability you'll put a nice little tune in there as well."

Aside from writing and production, the actual playing of the record is often Stock and Aitken's own work too.

Aitken: "We had a period when we were using Fairlights and PPG systems, before technology became user-friendly — we would usually carry a programmer or somebody at that point. We went through about three keyboard players in nine months, mainly because they couldn't handle the pace.

"It's really by a process of having to get on with it that we basically do everything ourselves, except the vocals... we do those too, sometimes. We get a sax player in occasionally because we don't play sax. But we're both keyboard players and guitarists."

Stock: "We're actually very talented."

Aitken: "You can get stilted and bored sometimes, but on the other hand if you know what you want it's pointless trying to tell somebody else how to do it if you can do it yourself quicker. It's very much the way things are going these days."

Speed is an important word in the dynamic duo's vocabulary. They can knock off a single in...

Stock: "To write, record and mix?"

Aitken: "A day and a half?" Stock: "A day and a half." Aitken: "I would say on average about three days. A lot of that time is spent on doing backing vocals, and the vocal itself. Usually a lead vocal is done in two or three hours. 'Toyboy' was done in 35 minutes. She tracked it eight times, and every time was identical.

"It's an interesting point that when they came to us Bananarama were not known as the world's greatest singers. When we started to get into the nuts and bolts of what Jolley and Swain had been doing to them — they'd been spending the whole day, three of them, doing a vocal — at the end of the day it sounds just like a slightly smoother version of what we do in ten minutes. We like the edge that we get with the girls."

Stock: "And also, through the years, this recording technology has enabled people to waste a lot of money. After all, it's the producer who's wasting the artist's money, it comes out of their royalty. I wouldn't like that responsibility of spending an artist's money, particularly if I was not being particularly competent. I think our job is to make the best record we can in the shortest amount of time, spending the least amount of money."

Aitken: "I think technology has got a lot to do with it. We had the multitrack of 'Le Freak' in here because one of the guys here was doing a remix. You put the faders up on ten and it sounded like the record. Bob Clearmountain engineered it, it was brilliant engineering, it sounded wonderful. But he must have spent two days getting that drum track down, dropping in, getting it all in time. That single might have taken five days, but two days of that would have been getting drums bass and guitar absolutely tight.

"Whereas, for instance, on 'Roadblock' I was putting a rhythm guitar down. I put it down all the way through, but I picked out two bars where it really jelled, sampled it and put it all the way through."

Vocals are no exception to this treatment.

Stock: "It's just using technology to its best advantage. I use three or four different girls to do backing vocals. Not on any one session, I've got a stockpile of people who we know are good. Having sung one chorus in three part harmony, and got it tight, I don't see that we should make them sing another one. We just put it into the Publison (a French sampler) and play it into the track."

Aitken: "Four years ago we would have done all that and then we would have put it on half-inch and spent two hours getting them all synced in..."

Stock: "Spinning them in from tape... and we can knock off certain words that we like and use them elsewhere in the track. It's a much more inventive process and very quick. It still won't make the singers sing well, they have to sing well."

At this point Stock and Aitken dash off to produce another hit, leaving me with the remark that they'd like to work with Cliff Richard and Paul McCartney, providing that they can be persuaded to do a pair of typical SAW dance records. "It's easy to write ballads," says Stock, "you just sit at the piano and be miserable."