Is there any type of traditional (lets say pre-radio/record industry era) music which originated in the United States that did not come from either the South (lets say Virginia and Appalachia through the Ohio river valley to central Texas) or from African-Americans and others migrating out of the South.
What forms of music are traditional to places such as the Midwest, Pennsylvania, Upstate New York, or New England?
Well, 'round here we gots Finnish Reggae.
In places like Wisconsin, Minnesota, and Iowa, a hefty percentage of the state was settled directly by European immigrants in the 19th century. The music of the pre-radio/recording days would have been a patchwork of the musics of the various immigrant groups: Irish, German, Scandanavian, Belgian, etc. etc.
For an idea of the variety that would have been involved, see:
Well, I polka’ed with Bruce Springsteen, with Danny Federici on the accordion, at the Boss’ concert in Milwaukee. They played “The Beer Barrel Polka”. I guess I consider that northern music.
How about the Chicago blues?
Whaling songs and sea shanties in New England? Stephen Foster lived in Pittsburg and Cincinnatti, and even though he’s not a genre, he is responsible for a bunch of “American songs” that have become classics.