I was indeed thinking of the Detroit school (this city is something else when it comes to music). I'm actually a huge Kraftwerk fan (Trans-Europe Express man, what an album) but although they're definitely pioneers and inspiration of almost every electronic music genre, I wouldn't qualify them as techno artists. They're more a synth-pop / kraut/experimental band, with a lot a vocals and usually slower tempo than proper techno. Same goes with house music, I always thought it was a German thing, but it's actually another Black American subgenre born in Chicago.

That said, if we really want to go back to the origin of electronic music and instruments, we would be in Germany (sound synthesis) and France (sampling) in the 50s and 60s with the work the elctroacoustic / musique concrete composers like Stockhausen and Pierre Henry (check out Messe pour le Temps Présent, absolut classic). I am totally passionate by all this and actually teach in music history and sound creation at a College in Montreal.

So on a comment about the things black Americans have given us your first thought is "Kraftwerk, some white guys, actually invented techno." Which is factually untrue. Yes, Kraftwerk and other Kraut rock bands were an inspiration to all forms of electronic music but what they were doing was not at all techno.