Orchestral leap in the dark

"In those days, a month was a lifetime," says Andy McCluskey, OMD's frontman. "Phil Oakey has issues because he knows we started before the League and it pisses him off. Electricity came out in May 1979, before [Numan's album] Tubeway Army. Later, I heard Numan bought a copy of it, told his management he liked it, then they phoned us up and asked us to support him on his Cars tour. Suddenly, everyone said we were copying him! The politics were ridiculous. But Depeche Mode definitely started because of Electricity - Vince Clarke heard it in a club."

This year marks the 30th anniversary of OMD. They are reuniting for a tour, performing their 1981 LP, Architecture & Morality, arguably the most experimental album - and the most pretentiously titled one - ever to sell four million copies.

The gregarious McCluskey, the quiet Paul Humphreys and enigmatic third member Winston - a tape machine bearing the slogan, "Keep Music Live" - began making music together in 1977. Friends since primary school, the pair would meet in Humphreys' house to devour the proto-ambient/electronica of "krautrock" pioneers Can, Neu! and La Dusseldorf. Techno-boffin Humphreys built instruments using old cereal packets and sticky-back plastic.

"We had this thing called a Tubaphone, a long cardboard tube with a mic in one end which we blew into," recalls McCluskey. "We were making noises out of everything we could find. It was extremely experimental." But it would prove extremely popular, much to their astonishment. "We thought we were doing this weird artsy-fartsy thing," says Humphreys. "We didn't realise we were writing catchy pop songs. It wasn't a notion you'd have thought would be successful: two guys playing electronic music in punk clubs that all our friends into prog rock thought was rubbish." OMD would later be dubbed "Orch Man At C&A" for their clean-cut bank clerk "anti-image".

It was Tony Wilson, boss of new label, Factory records, who said, "Actually, guys, this is pop music!" Wilson offered to release Electricity, while gig opportunities arose with fted Factory band Joy Division. "The first concert we ever played was at [Liverpool club] Eric's, with us supporting them," recalls McCluskey. "I remember watching Ian Curtis and thinking, 'He's dancing as badly as I do. Is he copying me?'"

McCluskey's legendary dancing, he says, stemmed "from the perception that we were making boring robotic intellectual music that you couldn't dance to. I was trying to say, 'No, no, you can dance to it, look, I'm dancing to it - there's energy, passion'. Because in the early days, there was a large group of journalists who believed rock'n'roll should be played on guitars, not synthesisers."

OMD defied these critics with a string of high-charting singles - Messages, Souvenir, Enola Gay and Maid of Orleans - "by distilling the electronic and experimental music we'd been listening to into three-minute synthpop. It didn't seem like a recipe for world domination. It just happened to work," says McCluskey.

Like their heroes, David Bowie and Brian Eno, OMD were bringing avant-garde music into the mainstream. "We were inordinately proud of ourselves for walking that tightrope, " McCluskey says, "appearing on Top of the Pops along with Elton and Cliff while being experimental! And radical! And subversive!"

Humphreys calls fame "the downside of making music - we found ourselves in that position by default." Did he do anything he later regretted? "Nothing that I'd want to expose to the general public." Nevertheless, success was a Pyrrhic victory. In fact, it proved their undoing.

"It sounds very sad," says Humphreys, "but I don't think we did celebrate, precisely because we never contemplated it happening. How stupid! I wish we had enjoyed it. But we were so determined to be serious and not be pop stars." McCluskey agrees. "We were terribly precious, po-faced and arty. We were going to change the world by writing songs about aeroplanes that dropped atom bombs. We were young.

"We started quite synthpop," he continues, charting OMD's progress, or rather, decline, "then on our second album [Organisation, 1980] we were more Joy Division-influenced; darker and more gothic. Then we went all beautiful and choral on Architecture. When we discovered that, despite the millions of sales, it didn't change the world, it was a bit of a disappointment."

So they recorded Dazzle Ships (1983), a defiantly uncommercial album of sound collages and radio samples that sold disastrously, even though it has been rehabilitated as a prime example of pop derring-do. At the time, however, it bombed. They "reeled in some of the radicalism" on Junk Culture (1984), the title a wry comment on the failure of Dazzle Ships to connect with the populace; it included Top 20 entries Locomotion, Talking Loud and Clear and Tesla Girls. In the mid-1980s they were bigger in the States, with albums like Crush and the Stephen Hague-produced single So in Love. By the end of the decade, OMD Mk 1 were finished.

"The wheels had come off, so I decided to bail," admits Humphreys, who spent the 1990s as a house husband. Then, when it came to finding work again he realised he was "unemployable outside the music industry, so I sneaked back in with a record label [Telegraph]. But then my marriage fell apart. That kicked me in the teeth. I was so messed up I lost all enthusiasm for the label."

"Paul and I fell out - not violently," says McCluskey of the split. "He blamed me for the collapse of sales in some respects. Mainly we were sick of the sight of each other: we'd spent all our adult lives together. But all I'd known was working with Paul, so I near as dammit had a nervous breakdown. I didn't know what to do without him."

Virgin persuaded McCluskey to carry on alone as OMD: he enjoyed massive success with the three-million-selling album Sugar Tax (1993), but by the middle of the decade he was out of favour once again, critically and commercially. Not for long, though. By 1999, he was back, not as OMD (which he wrapped up in 1996), but as writer and producer for Atomic Kitten. "I'd decided to listen to Julie Burchill and got my head around the beauty of the disposable pop artefact," he says. "The 18-year-old me would have been horrified."

These days, Humphreys also records as Onetwo with Claudia Brucken of the 1980s' "Abba-on-acid" band Propaganda; he compares getting back together with McCluskey to "riding a bike". A new album is being considered. "We're far too civilised to have really fallen out," says his partner. "I just hope that by the end of this year we won't be sick of each other again."

He's looking forward to road-testing their latest anti-image. "We're calling it the reservoir bank manager look," he laughs. "We were boring bank clerks at 20, now we're fat and middle-aged, so let's be bank managers with attitude."

• OMD play the Armadillo, Glasgow, on 15 May. Onetwo's debut album, Instead, is released on 12 February.