"Architecture in general is frozen music."
Friedrich von Schelling (1775–1854)

Music to live in. Music to travel through. Music as a mental map of the onrushing future, as we joystick through the ghostly green-image of cities that vanished centuries ago, or may never be built, as our feelings for and memories about unlived lives in unreal places tracked through us, impalpable but also irresistible: we start to move, we break the glass . . .

"To me," says Kraftwerk's Ralf Hutter, polite and precise as ever, laying his quietly forceful claim on everyone's technological present, "to me, music has always been Virtual Reality. I go into music and this is my space; so all this [he means, of course, the currently fashionable excitement for life in Cyberworld] comes as an additional force, sure. When you play "Autobahn", or "Trans-Europe", you can actually smell the burning tyres. You enter a different space. When you play "Trans-Europe Express", you can actually travel through Europe. Virtually. Now with computer-generated images, you can extend that into graphics and visuals."

We wonder if this is true. We feel, nonetheless, as if we've been programmed to ask the next question. Do you, we ask, need visuals?

"At some point it's a reinforcing element, but it'll block the mind if it's the wrong program. For instance, you hear a record, you get into a virtual reality, and a week later you see a video. But if it's not compatible with your virtual reality, you lose something."

We've seen the future of rock 'n' roll. In fact, we've been there, flying by in gleaming machines. Black music, turning itself inside out around the axis of a lifted melody in a curious near-novelty record almost a decade ago: Bambaata's Soul Sonic Force, and "Planet Rock", suddenly up-ending everything we'd convinced ourselves we knew about African-American technologies of expression. After the saxophone and jazz, the electric guitar and R&B, the digital sampler - and hiphop and House. A transformed cultural landscape, where the lines from Darmstadt to the Boogie Down Bronx were, well, suddenly traceable.

"Trans-Europe Express," sang the stolen tune brightly. Learn a new language. Think everything through again. Et in Nintendo ego, endless endless endless.

The day the robots came back to claim their place, we were taken by surprise. We'd been joking, after all, for a while now, about their absolute triumph everywhere, their pervasive underground effect gone suddenly pervasively overground. The absurd fact that the fab faceless four were suddenly (secretly) the most influential group of all time. Fact, because the record they were presumably currently working on was awaited with the same all-across-pop cargo-cult fervid anticipation that the next Beatles/Stones/Dylan product could once always engender: waiting for postcards, down from the mountain, to order the next bit of your life by.

Absurd, because it's absurd. They're from Dusseldorf! What can they possibly know that we don't?

"If," said Sam Phillips, of Chess studios, long ago, "I could find a white man who had the Negro sound and the Negro feel, I could make a billion dollars." Sam found Elvis.

"Kraftwerk were good," said Juan Atkins, known as Cybertron, not so long ago. "I thought if I could make them funky, I could take over the world." Juan, with Derrick May and Kevin Saunderson, founded Detroit Techno. The sound of colonnades and palaces, motorways and morsecode, in molten sensual soul-motion: and somewhere in the back of it, Ralf and Florian, this most unlikely inspiration. Postwar Germany and post-slavery black America, rebuilding culture from nothing, from ruins and darkness: and finding – against all expectation – some fragment of a shared universal language, a fantasy space they could both call home.

"We always tried to reduce," says Ralf. "To play the least possible notes. That's definitely one of our ideas (…) I think that's also a part of where we come from, in motion, where we play the minimal soundtrack, and you add the rest yourself, rather than that baroque overkill. Too many notes, that has to do with fear, when you're standing onstage, you trample on your keyboard, play ten notes with ten fingers, rather than one note very quiet.

Examine their trick, and call it simple if you will. You didn't think of it. To cut the voices down to machine-mumbles, and to let the machines sing. They're only instruments; you're the motor. But as any player will no doubt tell you, sometimes an otherwise inanimate object lets you tell things you didn't know you knew.

"Sometimes you think of something ahead, and then you play it. That's one way of doing it. Then you play while you play; I have singing fingers, talking fingers. Florian has a talking typewriter. While you press the phonetics and the letters, you hear them; so, speaking typewriter…

"It's distorted from industrial product, part of a big Siemens computer from the old days, and Florian took it, and we persuaded a technician to modify it. That's the voice you hear on a lot of our records. I play mostly keyboards, plastic knobs, just black or white notes. There's nothing to it. As we go along, I sometimes don't know where it's coming from, and that's the best way I can explain it. It's nearly automatic, very relaxing and easy and the music is like a gift coming through your fingers. It doesn't happen all the time, and you have to work on it afterwards, edit it and so on. I'm aiming for an improvised situation with the computer."

Always before, a Kraftwerk LP arrived, and we listened and thought, yes, but… And in a week we were hooked, and invaded, and changed. Metal pod-people, waking up to find ourselves absolutely the same and subtly theirs. On one level, The Mix only reworks old favourites: "Computer Love", "Autobahn", "Radioactivity", "Music Non Stop"… Smart move, too, in the face of impossibly high expectations you can only change the world so often, and their obsessions have been taken up everywhere, developed beyond anyone's ability to keep up, by bedsit technicians in Chicago, Brussels, Osaka, Sheffield, Rio, Goa, wherever.

But this isn't the point. Their pre-eminence comes from having utterly grasped a fact of the modern studio world long before anyone else. The content of a Kraftwerk song has never been its tune or even its words, never the sheet music score that others could play. It was always the film it projected, or projected us into, the charged virtual space it created and let us loose in.

"Without loudspeakers," says Ralf, clarifying matters at least as obliquely as Kraftwerk's new record, "without loudspeakers, you wouldn't hear Kraftwerk. You couldn't play Kraftwerk on the piano. Notes make no sense."

Music to live in. Music to travel through. Music as an interactive use-model of the fiction-zones we conjure with, to keep us sane, mobile, smart and creatively spooked: and at the fall of night, this city's made of light…

"With Kraftwerk, notes are useless. You wouldn't be able to hear it."

Special thanks to Jon Savage and Biba Kopf.