By 1981's Computer World, Kraftwerk's quest to become one with their machines was pretty much complete. The vocals are suffused in eerie electronic processing, as though cyborgs had grabbed the mic; the zapping rhythms sound less like drums than bursts of pure electricity. So much pop music can be traced back to their digital Big Bang: They gave electro its syncopated beats, and "Numbers" was sampled on Afrika Bambaataa's "Planet Rock" and scores of other songs. The band's gentle melodies, meanwhile, make their future-past a remarkably reassuring place to visit.