By the end of the 1960's there was quite a number of German jazz bred musicians experiemnting with rock rhythms - rock was their point of reference in most cases, although some played with black soul bands temporarily based in Germany. (I played in a local fusion band - Zyma - whose bassist was with Archie Bell & The Drells when they were over here.) Dave Pike & Volker Kriegel, Doldinger & Ingfried Hofmann were just the best known. Take Wolfgang Dauner's groups, Etcetera in particular, into account. Mal Waldron gigged with Embryo. There was a local group called Xhol Caravan which just had a reunion concert.
You can find info on all these albums as well as links to YouTube samples on discogs.