I'm Mexican and I enjoy history and even though Norteño music "is not my cup of tea" I moved to California, USA and became very curious about this music and the regional history.

Through NPR and PBS shows I have learned about the origins and the transition from music brought in by Germans and Eastern Europe immigrants that arrived in northern Mexico and the south of Texas in the 19th century, music like traditional Waltzes and Polkas, were transformed by Mexicans and Mexican Americans to what is known today as Norteñas or Norteño (from the north) music.

I was looking for 1 hour radio show that I heard on NPR years ago that has sample music and historic details about what I mentioned above instead I found a smaller show that has good content and a simple explanation about how things happened:

Here is the ~4 minutes NPR radio clip, with before and after sample music:

http://www.npr.org/2015/03/11/392141073/how-mexico-learned-to-polka

From the clip: "Me and my buddy listened to this German bands when we went home he would whistle the tunes back to me and I would pick them up with the accordion"

One simple observation given in the 1 hour show was that early Norteño music was basically a Polka but with an accelerated beat.

Some of the pioneers of this music have had interviews about the origins and evolution of this music, I think some of them are still alive. I will add names and media links that I find.

Something to keep in mind: the polka wasn't just a German dance, it was universal. Mexico just hung on to it in a purer form a little longer and more up-front than most.

The waltz (from Vienna), polka ("the Polish dance"), the schottische (you guessed it, the Scottish dance) and mazurka (from Hungary edit: brain fart, also Poland) were danced by just about everyone young and hip, everywhere that western/European culture had a presence. The moneyed classes did the big four dances at balls, the bourgeoisie in the cafes, the peasantry in village halls and at pounded-dirt crossroads.

Before the waltz and its cousins went viral, folks danced in sets - in lines and squares, quadrilles and circles. Picture the balls in Jane Austen's books, or Dickens, or Gone with the Wind -- everyone is dancing geometrically, being chaperoned by the formation itself.

The evolution from mathematical formations to separate couple-units caused a huge stir; the older generation was quite sure the young folks were dancing right straight to hell, arms (shockingly) clasped around each other's waists. The younger generation didn't care about hell, or at least not enough to stop -- everybody waltzed/polka'd/schottisched/mazurka'd, everywhere. Remember the Macarena? That was a blip, a mere ripple, compared to the wave of popularity that swept the 3-beat waltz and its 2-beat polka cousin around the world.

A generation or two later, the ragtime era came along and young couples not only swept around the ballroom, they waggled their butts back and forth in one-steps and two-steps, leaned into tangos -- because the music had gained a jazzy backbeat courtesy of African influence, and because the newer uncorseted dress styles meant the women could -- and again, the older generation freaked.

Another few decades go by, ragtime turns to swing, and the couples stopped progressing around the room and stayed in one place -- which meant you could pick a dark corner behind a potted palm and really get in trouble; cue older-generational-freakout, 1940's version.

Two more decades, and the kids who grew up swingdancing -- grabbing onto each other in a way that would've almost landed you in jail a hundred years back -- get upset when their kids stop touching each other and simply shimmy/boogie in place.

The polka survives today in Mexican culture partly because it's survived everywhere, because it originally went everywhere. Traditional fiddlers in Quebec, Ireland, Vermont, Louisiana, Norway, France, Italy, Russia and everywhere in between all know and play plenty of local polkas, each with their own regional style.

And in every region, the quick, perky one-TWO-one-TWO backbeat of the polka threaded its way through the evolution of pop styles -- it turned into first the ragtime one-step, then jump swing. It's still out there -- listen to a recording of a Bavarian beer hall polka while saying "boots and cats and boots and cats" or "unts unts unts" and you'll hear the shared DNA. ;)

Now, is the polka the true source? Or is it merely the mid-19th century inflorescence of one of the universal human grooves? Do we as physical creatures just naturally like to move to a 120 bpm groove with a sharp off-beat, as part of our expressive vocabulary? That's a whole different discussion.