On a number of the Tex-Mex records issued by Arhoolie, the album notes point out the German influence on the music. The tune known here as "Roll Out the Barrels" shows up on a lot of Tex-Mex records under various names. On one of the Arhoolie records, there's a polka called "La Raspingona" that also showed up on a recording I own of a Lithuanian band. I suppose it could have been exported from Germany to both countries. Or Mexicans originally came from Lithuania, a theory that Thor Heyerdahl was investigating when he died.