Here’s a good band name for ya:
Los Nahuatls

One time many years ago, I was at a beach right by the town of Maruata in the state of Michoacán, was extremely surprised and intrigued when I was told that the people of that town spoke Nahuatl as their second language, when everywhere else in the surrounding region spoke Tarasco as their second language.

If I had to speculate, I’d say Maruata was founded as an Aztec outpost at some point in time, then when the Tenochtitlán fell, they were left to their own devices, on their own. It has to be something like that, right? Fascinating little cultural/historical footnote, in any case.