The experts in atmosphere from Donegal tell Tony Bacon tales of the hooded man, the lower Prophet, and the champagne bubbles.

Two days after Clannad had won a BAFTA award for their soundtrack music to the TV series 'Robin of Sherwood', founder members Ciaran and Paul Brennan are still drinking champagne. In fact, one gets the impression that they're using two-day-old, well-worn glasses for the purpose.

As with most TV awards, there is a distinct feeling that the winners are superficially impressed that they should be so chosen, but underneath are somewhat bemused by the whole affair.

But who are Clannad? Ciaran pours another glass of bubbly and looks up. "We started off as a folk band in the Seventies, totally acoustic: flute, harp, acoustic guitars, mandola, double bass, vocals. By the time the mid-Seventies came in there were Prophet-5s and so on in the studios. We'd always played folk music that has a drone system to it, like pipes. But we didn't play pipes, so we'd simulate that sound on a synthesiser in that style — they are today's tools. We didn't say, oh, we'd like to sit down and learn to play the pipes — that takes 25 years — we just played the music on the instruments to hand, with an awareness of the music we're dealing with."

And here is the clue to what it is that makes Clannad's music so interesting: their particular opposition of acoustic and electronic instruments. Listening to their beautiful album of songs, 'Magical Ring', or the less impressive but equally atmospheric Robin soundtrack LP 'Legend', the musically aware ear cannot fail to prick up at the artful combinations that the group manufacture.

But of course you don't happen by chance upon this kind of sonic understanding. "We rely a lot on our ears," says Ciaran, and Paul immediately reprimands him for such an obvious comment, saying, "Everybody does." But Ciaran's right. Listen carefully, and you won't go far wrong.

Paul explains in more detail that Clannad, having made six or seven LPs prior to 'Magical Ring' — "call it an apprenticeship" — had, in that time, to concoct arrangements from the flimsiest of musical sources. "We dug up obscure songs from the weirdest places," he says, "half-melodies of things, no chords, and we sat down and totally re-orchestrated the piece. We were doing that for eight years. In terms of writing, that's just like composing a song. It's the same process, surely it is."

What is more, Clannad's evident merriment at pitching real and synthetic sounds in such admirable contexts was not matched by the old guard at home in Ireland. Ciaran elaborates: "We were dealing then with songs that were very old, and we were deliberately putting on them a contemporary slant, no bones about that. People didn't like it straight away — they said, 'You shouldn't do things like that.' Once they said that, of course, we just had to do it even more."

But could people get so upset just about the treatment of a few old traditional Irish songs? "Oh yeah," says Paul, "we got that for years. We were taking songs that were sacred.

"But what's really interesting is to match sounds from, say, the DX or the Emulator with something like a real flute or a real double bass, and come out with a really different sound as a result. Of course, you need someone in production and engineering terms who can capture that."

That person is about to be producer Steve Nye, who will guide the group — Paul and Ciaran, plus their vocalist sister Maire, extra musicians Noel and Patrick Duggan, a drummer, and keyboard player James Delaney — through five or six weeks' recording from mid-March at the Manor studio for another songs album.

More white sparkling wine finds a trio of greasy, much-mouthed glasses. "You see, 'Magical Ring', that LP went two ways," considers Paul, "it was un-produced and well produced. 'Legend' is a glossy sort of production, very sheeny and sweet. The next record is back to songs, back to the edge but with the production.

You're probably wondering when we're going to mention "Harry's Game", aren't you? That was the song that made Clannad's name: another TV theme tune, a big hit and another wonderfully atmospheric mixture of electronics — a Prophet — and acoustics — 110 tracked-up voices. In hindsight, that must have been a turning point for the group's favours? Ciaran seems unsure. "People change a lot. We were still on a German tour at the time, hadn't a clue how the record would go. We knew it was nice."

Paul gets into more detail. "I remember when we'd done it and we were out in my house and saying, right, now it's done, and a conversation happened where we considered that it might be too down. I thought it had something."

"It gave us goose pimples," says Ciaran. Me too. Their Prophet still gets used, despite upstart contributions from fresh-faced DXs and Emulators. The Prophet has a mellow tone, they say. "A lot of engineers don't like it now," reckons Ciaran, "because it doesn't have 'bite', which is what's fashionable just now. But I've always thought it's an instrument that blends well with voices."

"I love the lower end of the Prophet," says Paul, "it's unlike any other synth. I've fiddled a long time with the JP8 and the Juno from Roland, and they have a totally different lower end."

I tell the boys that this is because the Japanese hear with the other side of their brain to westerners, and therefore need a different kind of sound to satisfy them. Then I swig some more champagne. "Yes, yes," says Paul, baffled.

"When you bring an Irish harp out into the wind," says Ciaran, desperate to change the subject, "you hear the wind blowing through it, a lovely sound. But it's very hard to record well, whereas you get a line from a synth on the harp program... we'd be very aware that we were using a made-up harp sound on synth as opposed to going for the real thing."

There is some clattering of glasses, murmuring of airports and a return to Ireland, and Clannad are ready to go. I'm glad they're preparing another songs LP. Very few soundtrack LPs survive separation from the relevant pictures. "People could argue that 'Legend' could have been better," says Paul, "but we're our own best critics. Let's face it, we've achieved something in TV music today that is different." And wins awards. And, presumably, gives them freedom to spend even more time on their real music. Good.