The oldest music school in the Americas is in Mexico City. Oaxacan musicians studied with Strauss in Vienna. Mexico was quite civilized and cosmopolitan while the future US was still a backwater outpost of English mercantilism. A lot of the German influence in Mexico came from Spanish/Mexican initiative.

Another possible source of German influence was the conquistadors. Many of them were teutonic mercenaries. Having ejected the Moors from Spain in 1492 after 200 years of hacking at them, Ferdinand and Isabella were only too happy to pack their armies of mercenaries overseas where they could not easily stir up trouble in the royal court. Many hispanic surnames such as Gonzalez and Gutierrez are from teutonic names.

The Christian crusade in Iberia resulted in a lot of other dislocations, including the expulsion of Iberian Jews (many to the Netherlands) and in lingering enmity between Muslims and Christians which you may encounter to this day.