It's kind of like this already! Most non-Western music is just referred to as "world music" nowadays, so it sound impressively to specific for one to be able to hear a folk piece and say "that's Javanese". And then for a second piece: "that's Javanese too". And the two pieces would sound very similar. But in Java, the two pieces would be understood to be very different. Sometimes all it takes for two pieces to be considered to different genres in folk culture is something as simple as a different playing style for a specific instrument.

Now, to many that would sound like something laughably minuscule when explained to us (Just the playing style?! Harrumph, they're still basically the same genre) and yet I bet that even a very musically un-educated American would hear a ragtime piano piece and understand it differently than a boogie-woogie piano piece even though

1) Those two genres are not even popular anymore, to the point where the American may not even be able to put a name to the two different genres

2) The two genres are mainly separated by just the way the piano is played