The story behind electronic chart-toppers Trans X is a fine example of how esoteric synth music can be made commercially marketable. It's also a long, winding history of countless line-up changes and record remixes.

Let me give you some idea of just how quickly French-Canadian electro-poppers Trans X have risen to fame and fortune. When their single, 'Living on Video' went into the Top 20 in its second week of release, Polydor's parent company in Germany shipped all their available press information on the band over to the UK. Biographies, photos, videos, all featuring composer Pascal Languirand and sultry singer Laura, allowed the publicity machine to swing into action, and at least a few details about the band became public knowledge.

But when Trans X turned up in London for a round of meetings and interviews, consternation reigned. There was no sign of Laura, who had apparently left the band two years ago and returned to modelling after discovering that the touring side of the band's existence disagreed with her. There was no sign, in fact, of the rest of the band, who'd all been sacked at one stage or another as Languirand went back into the studio to record almost entirely with synthesisers. And Pascal was now accompanied by two new female vocalists - Sylvie Daviau, who is very French (but comes from Canada) and Jean-Elliot Manning (who is very American, but lives in Montreal).

This was the signal for a hectic updating of the hand's photofiles and biographies, which had to be fitted in between radio and TV appearances and interviews such as our own. And the full picture is even more complicated than it already appears, because as some sharp-eared types may have spotted, 'Living On Video' has actually been released three times now, most recently with a slightly modified mix. So what has the band been doing since the song was first recorded, back in 1983?

Pascal Languirand explains. 'At the same time we recorded 'Living On Video' I did a whole album called Message on the Radio. That was released on Matra Records, which is Polydor's subsidiary in Canada, but the album wasn't released in the UK. After it came out I put together a band so we could play live. I played keyboards, and there was another keyboard player, a bassist, a guitarist and a drummer. So we played around Canada for a while, and then 'Living On Video' was released again.

'It wasn't until earlier this year that I was asked to remix the single because it was going to be released a third time. Obviously somebody at Polydor had confidence in it, because if had already been a hit on the Continent. I remixed it very quickly, and then we heard it had gone into the UK chart.'

We'll return to Languirand's pop exploits later, but first, it's worth recapping on his previous musical career. He's already released two solo albums, De Harmonia Universalia and Vivre Ici Maintenant, which could quite justifiably be described as being in a cosmic vein. How did those albums come about?

'Well, very much in the same way that Klaus Schulze's solo albums happened. I was a drummer originally, like Schulze, but I heard some synthesiser music and thought I had to get into it. The first synth I got was an old Farfisa Synthorchestra, which at least I could play chords on. I also played guitar, and had the Roland GR500 guitar synth system coupled with a Moog Taurus bass pedal unit.

'Luckily my family had good connections with the TV and film industries in Canada, and I was able to get some work recording a soundtrack for a TV series called Vivre Ici Maintenant. That was about very esoteric subjects, something different every week, so it needed this kind of 'cosmic' music. Then I recorded De Harmonia Universalia which allowed me to use more synthesisers and the Korg Vocoder.'

Both albums were released on the Minos label, but it's unlikely you'll find copies now other than by mail order from specialist distributors such as Lotus. Yet in spite of their obscurity, they're fine examples of the flowing guitar/synth style popular in California (I'm thinking here of Bernard Xolotl and others), and just the sort of thing that's likely to turn up as backing music for a Horizon episode about the mating cycle of the killer ant.

De Harmonia has five tracks, the titles being 'Inesperdistan', 'Abalii', 'Atlantis', 'O Nos Omnes' and 'Nova'. The opening's particularly powerful - lots of deep bass Taurus notes followed by Baroque choirs of vocoder chords chanting delicate, sensitive French vocals.

"Luckily my family had good connections with the TV and film industries in Canada, so I was able to get some work writing soundtracks."

And despite the fairly limited instrumentation, the sound never allows itself to get cliched or outdated, which must say something for Languirand's tasteful use of effects and his mix of acoustics and electronics. 'Abalii' features acoustic piano as well as gentle guitar synth lines, while 'Atlantis' is heavier, with some crashing acoustic guitar and piano chords and, again, some thoughtfully delivered French vocals.

The sequencers come into play on 'O Nos Omnes', which underpins the choir and guitar synth sounds with a churning analogue sequence, while 'Nova' is an indication of the pop style to come: a more melodic sequence, and more complex layers of guitars and sound effects.

Languirand was keen to try something a little more commercial, however, and says he was able to apply the same compositional techniques to writing some more conventional songs. What was the first attempt he made at a commercial song?

'It was called 'Living On Video'! That really was the first one I did, although in all we did seven tracks for Message On The Radio. They're all more or less dance tracks, but I wanted to use some of the subjects I'd had in mind for the more 'cosmic' pieces. 'Living On Video' was written after I'd seen the film Tron. It was really about what it would be like to have to live inside some kind of video machine. And then there's '21st Century', 'Digital World' and so on.'

In fact, 'Digital World', which formed the B-side of the single, is the album's outstanding track, in spite (because?) of the fact that its vocal content is sparse and its synthesiser work verging on the experimental. It was written with occasional synth player Steve Wyatt, and used some larger polysynths such as the Elka Synthex, which Languirand chanced upon in the studio while recording the album.

'We recorded at Ultra-Son studio in Montreal, which is a nice 24-track with a Soundcraft desk. They had a few synthesisers there which I used a little, but mainly I was using my own equipment. After that I sold everything to put the band together, but the studio now has an Emulator II which I can use while I'm working there.'

But the equipment list for 'Message' is quite formidable - Roland Jupiter 4, Jupiter 6, CSQ600 and TR808, Korg VC10 vocoder and Polysix, Oberheim OB8, DMX and DSX, Elka Synthex, guitars, Simmons kit and Mattel drums. And as you may have spotted during the Trans X single's recent heavy airplay, there's also a bit of Casio VL-Tone on 'Living On Video', and elsewhere. For his own part, Languirand is at pains to point out that this is really a Jupiter 4, but anyone who's suffered the VL1's built-in Austrian Folk Tune a few hundred times can usually spot one a mile off... I know I could.

The composer adds: 'we only used the Oberheim a little, and the DSX sequencer hardly at all. I usually use the CSQ600 sequencer for bass lines, but recently I've been using the Roland MSQ700 as well, and of course that's much more versatile.'

All the album's lead vocal credits go to Languirand, with Laura filling in with a few Continental-sounding interjections. And her voice is still on the single, despite the fact that she's left the band. 'I didn't make a lot of changes when I remixed 'Living On Video' earlier this year', explains Languirand. 'The main ones were to thicken up the lead vocals with a little bit of ADT, and to change the drum parts. Originally they were recorded with a TR808, but the studio has bought a LinnDrum since then, so I overdubbed some of the percussion.

'There was no sync track recorded originally, so obviously I couldn't lock in a very complicated drum part to the original drums. I ended up playing some drum fills by hand from the LinnDrum, and I think it was quite successful.'

As already mentioned, the band's mentor took Trans X on tour after recording the album, after which Laura left to be replaced by Sylvie Daviau. 'I enjoy touring and singing on stage', she comments. 'But I think Laura was happier going back to modelling. Before this I was studying in Montreal - I'd done some studio work, but never anything like this.'

The new vocalist is Jean-Elliott Manning, who'd only tied up with the band a couple of weeks before we spoke to them. 'I'd worked with Pascal on a couple of other projects previously', she explains, 'but Trans X is something new for me. I studied in San Francisco and I was mostly involved with Salsa music there, and that has a lot of percussion and rhythm. I lived in France for a while and I really wanted to be in a bilingual environment, so Montreal was ideal. In the time I've been there I've done a lot of composition and produced a couple of stage musicals.'

"I want to integrate two musical styles, so that I can deal with cosmic subjects in a more commercial, pop format."

So doesn't the electronic pop of Trans X come as something of a shock to the system?

'Well, it's certainly all new to me, but I'll enjoy learning about it. I think electronic instruments are the place to be at the moment, so I couldn't have a better opportunity to learn up on them.'

Manning's big treat for the night after the interview was going to be a trip to Andrew Lloyd-Webber's Starlight Express, since she quotes Webber/Rice musicals as one of her greatest influences. But was her musical input going to change the direction of the band? Languirand: 'I've already started writing songs for a new album, and I'm experimenting more this time. I had one with a really funky beat, but it was quite coincidental that Elliott was into exactly that sort of thing.'

So how does the songsmith go about composing in the studio?

'Usually I have a basic idea for a tune in my head, and I write all the words later. At first I just set up all the synthesisers and play the tune 'live', getting as close to it as I can and singing any words that come into my head over the top. Then it stays more or less in the same form when I record it with the finished vocals.

'For the new album I want to look back a little more to the cosmic style I used to use. I want to integrate it more into the pop style so I can deal with the same sort of subjects, but in a pop format. I won't really go back to playing cosmic music, though - this is what I'm doing now. But I'll be able to use the Emulator II at Ultra-Son, using the sounds just as pure sounds. I won't he imitating real instruments with them: you'll be able to tell they're sampled.'

So will the new version of Trans X be able to tour? Will Languirand take backing tapes on stage?

'No, I wouldn't use backing tapes. We'd reform a band with an extra keyboard player, so that we'd be able to play all the songs. I'd very much like to play in Germany, where I spent some time and thought it was wonderful. And Holland and Belgium, where we had some success with the single, and of course the UK.

'But it's very hard for bands to tour in Canada itself. It takes three days to get from one city to the next, and that makes a tour very expensive. Sometimes you'd go and end up playing for a hundred people as well, so only the very big bands can do it. Even Canadian bands like Saga, who are huge on the Continent and particularly in Germany, aren't very well-known in Canada and don't tour a lot.'

After extending their stay an extra day to fit in more interviews, the band were set to return to Montreal to start recording the new album, and to think about another single. Does Languirand feel he's under pressure now that 'Living On Video' has been a hit?

'Not really, because the next album is more or less finished. I've written almost all the songs and it doesn't take very long to actually record them. We should be putting out a single before too long and the album will follow it a few weeks later. Then perhaps we can think about going on tour - if the next single's a success.'

For someone who's gone rapidly from the heady heights(!) of cosmic synthesiser music to the more down-to-earth - though financially more rewarding - world of pop singles, interviews and tours, Languirand is remaining admirably cool. Luckily, he seems to have a fairly stable background; his success isn't a matter of life and death to him. And as for his vocalists, Sylvie and Elliott, Trans X will be fun for as long as it lasts.

And for everybody out there plugging away with experimental styles of music and considering making it a little more commercial in order to achieve greater recognition, Trans X have become an object lesson in how to do it, regardless of whether their success continues. Keep an eye on them.