More has a metaphor for it. "When I was at art college I learned about Picasso but I didn't appreciate his work at the time because he'd been photocopied so many times that the quality degraded from his beautiful painting to a couple of licks of paint on a shit, made-in-Thailand piece of junk. That's what happens with a lot of different things. It starts, it's interesting, lots more people get on board, it gets exciting and then it all goes wrong."
Black, typically, prefers a scientific diagnosis. "I think it ran out of bpm (beats per minute). The range of dance music is 60bpm to 200bpm, which is pretty much the range of the human heartbeat. After 200bpm your heart blows up. It's like in fashion -- the length of skirts from the microskirt to the one that trails a few meters behind you. There aren't going to be any more innovations in skirt length."
Electronic music will be vital again, Coldcut said, when another generation discovers and reinterprets it. Until then, Black and More have decided that the way forward is songs. In the early 1990s they turned to abstract instrumentals, pioneering the sound that they playfully dubbed "funkjazztical tricknology" and everybody else called trip-hop. Now that music-making software has become so accessible, the challenge has gone out of it. Hence Sound Mirrors' ambitiously expansive remit -- bellicose rap-rock, frazzled electro-blues, paranoid rave -- and myriad vocalists, including Roots Manuva and Soweto Kinch.
"Check It Out Now the Funk Soul Brother was never going to compete with Honky Tonk Woman," said Black. "For a moment, yes, but not long-term. You will come back to songs that you can sing." He has a formula. "When you're bringing things to people, 60 percent that they can deal with and 40 percent new is about the right ratio."
Coldcut is nothing if not adaptable. Black and More became British dance music's first pop stars back when nobody was making much money out of it. Black lost his place on a government employment scheme when he missed a meeting to appear on Top of the Pops. When their major-label deal went sour, they founded the below-the-radar Ninja Tune, inspired by their trips to Japan.
"Our manager Jazz Summers said to me that we'd never make a record as good as People Hold On (with Lisa Stansfield)," More said.
"And I think we have. I've always kept that as a guiding force: the ninja art of turning around things like that and using it as an energy to drive you." That attitude produced their much-admired club night Stealth and the Journeys By DJ album. "We thought, `Right, we'll fucking show them,''' Black recalled. "And we did."
In the years between albums they have had, as Black put it, "many pies in the oven." They're surely the only act in the world whose collaborators include Steve Reich, Radiohead, Hari Kunzru and the British Antarctic Survey. For the 2001 election, they produced an audiovisual cut-up of political footage called Revolution. Three years later, they posted samples on an activist Web site and invited members of the public to help make a US equivalent. "I've got Mrs. Thatcher to thank for politicizing me," beamed More, who has a collection of 1980s protest memorabilia and grows misty-eyed at the mention of important industrial disputes of the day.