Kraftwerk's most recent record, the long-waited Tour de France Soundtracks - their first album of new material since 1986's Electric Café, and a variation on their 1983 single "Tour de France" - is a gleaming, sleek piece of work, a Mercedes of a record hand-tooled to perfection in the legendary Kling Klang studio. But in the 21st century, better electronic records are regularly dashed off in bedrooms with much less fuss by the likes of Four Tet, or roll off production lines in clinical corporate studios for Britney Spears and her ilk.
The group who helped rocket electronic music into the mainstream, and launch pop into the future, seem stuck sputtering on the launchpad today, unable to contend with the the brave new world they helped bring into being: the computer world predicted on the 1981 album of that name is now a prosaic fact, in music and life. And the stately rhythms that made "Autobahn" a global smash in 1975 have seeped into every area of pop until Kraftwerk are part of its DNA, as surely as James Brown or The Beatles.
But for Kraftwerk themselves, the problem this leaves is acute. Like workers in one of the power-plants their name refers to, they have been so brilliantly efficient at their work, they have made themselves redundant. They are yesterday's future, men out of time. As they prepare for rare UK shows next week, you have to wonder why they are still here at all.
The answer begins in the very different world where Kraftwerk were first assembled. The group's co-leaders and only constants, Ralf Hutter and Florian Schneider, met at Düsseldorf's Conservatory in 1969. They were bored classical students, fascinated with the repetitive drones of the similarly disaffected John Cale's Velvet Underground, and the car factory-aping industrial punk of Detroit's Stooges. Most of all, though, they were affected by the nation around them - a Germany shattered by Allied bombing, Nazi atrocities and guilt, its "economic miracle" awaiting a cultural equivalent.
It was as if the "pause" button had been pressed on German culture in 1934, Hutter would later consider. "It's a shock in the first place, this nothing," he recalled to Uncut magazine. "But then we take a deep breath and say, 'OK, it's a chance.'" They were fiercely aware of the place they were from - the industrial Rhineland that built the Nazi war machine, but could now be the source of something redemptive.
"After the war," they told the journalist Lester Bangs, "the German people were robbed of their culture, putting an American head on it. We are the first generation born after the war to shake this off, and know where to feel American music and where to feel ourselves. We are the first German group to record in our own language. We want the whole world to know our background." They liked the term "industrial folk music" for their work; it was "Central European", they said, "ethnic".
Forming Kraftwerk in 1971, they were inadvertently part of a general German movement of avant-garde, largely electronic music, including Can, Faust and Tangerine Dream. Their compatriots often reacted more directly to the violent tumult around them, as their generation confronted the Holocaust unleashed by their parents, the scar of the Berlin Wall, and the dread of living on the Cold War's frontline, as victims of occupation now, by both sides. Baader-Meinhof members flitted through the communes of Can and Faust in the night, and machine guns and dawn raids were common, as if the Gestapo had not yet been exorcised.
The jackhammering of cold concrete on stage by Faust, scalding their crowds with hot sparks as well as their sheer, remorseless noise, seemed to channel the times' brutality. Kraftwerk were always more contemplative, never exposing their feelings so nakedly. What they shared was a fascination with machines and the rhythms of industry, newly reproducable with synthesisers. "We try to treat them as colleagues," Hutter said of their alien new instruments, unreadably deadpan as always.
The scene was called Krautrock by a British rock press still smug about the war, and only too happy (as Bangs did) to make Nazi allusions. But as Schneider, Hutter and company settled into Kling Klang (a big brick factory space, phoneless and sealed off from the street, full of primitive and home-made electronic equipment) they set about reclaiming their country's war-haunted landscape, and giving it a future. "Autobahn", after all, refers to the motorways Hitler carved through Germany.
But the record they made in their own factory achieved a more benign and lasting conquest. Cruising up the US charts, it was a new sort of industrial funk, with synthesised, regular beats and a graceful prettiness suggesting both their classical start and another key influence, Brian Wilson. It was serene dance music, utopian and modernist, as the motorways themselves had once been. Schneider, Hutter and their bandmates at Kraftwerk's peak, Wolfgang Flur and Karl Bartos, eventually appeared as clanking robots in concert, even though they reminded Flur of "an odd string quartet": the cold future and quaint past coupled together, with Nazism's interruption removed.
The first answer to why Kraftwerk are still here is twisted into this history. Schneider and Hutton were never just electronic frontiersmen. Their music has deep roots in the time and place in which they grew up. They were helping to lift a curse on their country, using machines to make its culture breathe. They are regional musicians from the Rhineland, making music from the heart.
And yet their influence on the world has been vast. Like Bob Dylan with songwriting, they are a sedimentary layer in electronic pop, whether the musician concerned has heard them or not. During their classic run of albums - from their fourth, Autobahn (1974), through Radio-Activity (1975), Trans-Europe Express (1977), The Man-Machine (1978) and Computer World (1981) - they ruthlessly advanced into the cyborg ideal implicit in their music from the start. Punk in their own way, their drum machines killed prog's virtuosity as surely as any thrashed chord.
But they also tried to become part of Kling Klang, exploring the interface between the studio's machines and their minds, becoming absorbed in its wires at the expense of the world. Represented in public by glazed-eyed showroom dummies, with skeletal car- assembling tools for hands, they played with the public's fear of their ways. On The Man-Machine, too, they showed how antique their ideas were: its design was 1920s Futurist, and included a song, "Metropolis", referencing the doomed half-robot monster of Fritz Lang's classic 1926 movie. They also made sure to keep some of pop's most perfect moments on the production line. Haunting, desolate singles like "The Model" were unanswerable proof that they still breathed with human hearts. And, meanwhile, they casually depth-charged entire genres into life.
The most fascinating chain-reaction rippled through the ghettos of black America, where their cold funk, with its hints of smashed and brutalising industry, science-fiction escape, and narcotic, endless dancing, found an instant home, next to the more garrulous, fevered experiments of George Clinton. "I don't think they even knew how big they were among the black masses back in '77, when they came out with Trans-Europe Express," Afrika Bambaataa has said. "I thought that was one of the best and weirdest records I ever heard in my life. It was funky." Bambaataa's 1982 "Planet Rock" single, sampling "Trans- Europe Express" and another Kraftwerk track, "Numbers", among other sources, re-routed hip hop into pulsing electro.
In the Detroit suburbs, meanwhile, young black musicians Derrick May and Carl Craig worshipped Kraft-werk, equalling their glacial electronica with their own eerie post-industrial classic, "Strings of Life", and inventing techno. House, and hence rave culture, also bear Kraftwerk's mark, as do everyone from David Bowie and New Order to Aphex Twin and Daft Punk.
Bowie's fascination went so far that he moved to Berlin, helping to make its previously shunned concrete desolation the symbolic heart of Europe in the late Seventies. His album Heroes gave a nod to Kraftwerk with its track "V-2 Schneider" - allegedly the Werner von Braun-admiring Florian's darkly comic nickname.
In Britain in the early Eighties, meanwhile, synth-pop, with the likes of Vince Clarke standing robotically on stage pressing buttons, was briefly so dominant that guitars and gigs seemed sure to be extinguished now that the future was here. In 1991, Capitol launched a Kraftwerk campaign with the famous picture of Robert Johnson's primal bluesman, his head replaced by a robot's. The band's reclaiming of Germany's soul from American infection was now cheekily complete.
But long before that, Kraftwerk had started to retreat - first artistically, with Electric Café, then literally. Apart from 1991's hits reworkings for The Mix, nothing significant was heard from them until last year.
Hutter and Schneider said they were still working long hours at Kling Klang each day, converting it to digital technology and recording obsessively. But no music appeared. There was no sign of life from their studio machine and, with no fax, phone or street entrance, no search party could reach them. Their human helpers, Flur and Bartos, abandoned them. However much Hutter and Schneider denied it, they seemed overwhelmed by the weight of what they had achieved, unable to compete with themselves. But this perception misunderstands Kraftwerk's legacy. They were never only about the future or having to exist on a constant cusp. With their records about cars, trains, calculators and computers, they were trying to describe their present. At the same time, their music ached with nostalgia; they dressed like respectably suited 1930s musicians before they ever turned into robots.
This is what British musicians such as Metrovavan, Tele:funken and Max Tundra responded to in the late 1990s. Kraftwerk, Tele:funken's Tom Fenn told me, resonated with Seventies notions of what the future might be. They were a comforting memory from his childhood. In 2004, as we move through a weightless, fast-cut, constant present of instantly evaporating sensations, where Dizzee Rascal is shocking in April and respectable by May, Kraftwerk also evoke nostalgia for a time when the future seemed important - or even imaginable.
Finally, Kraftwerk still matter in the same way as the great classical music they were trained to make. Their sounds are lastingly beautiful, soul music discovered in the heart of the machine. Hutter and Schneider, both nearing 60 now, need compete with no one, least of all themselves. Their future music of old motorways has become timeless.
Kraftwerk play the Academy, Glasgow, on 16 March; Apollo, Manchester, on 17 March; Royal Festival Hall, London SE1, on 18 March; and Brixton Academy, London SW9, on 20 March. The single 'Aerodynamik' is out on Monday on EMIReuse content