my japanese teacher likes songs like those

I think it is because of influence from the mainland. People watch a lot of TV shows that are made in Tokyo. Most of my friends in school listened to Japanese music, not Ryukuan music.

That's true! My friend from Naha is going to college in Yokohama... There are a lot more opportunities in mainland Japan than in Okinawa. When I first learned Japanese, I learned Tokyo Japanese and most of my friends spoke Japanese like what I learned, but they sometimes had some Okinawan words in their speech. They also say さぁ a lot! 意味わからないですよ！

If Okinawan さぁ is anything like its mainland equivalent, it's basically a sentence-ending expression/particle that emphasizes what was said or implies that the stated thing is obvious.

For example, if you're with huge fans of the Rockets, you could say something after the game like
もちろんロケッツが勝ったさ。
Of course the Rockets won!

Basically I agree with you but people in Tohoku area speak in their dialect and we don’t understand what they say.
Tohoku is in the north part of Japan. They must watch TV shows that are made in Tokyo, still they speak in Tohoku dialect. I don’t understand why they don’t speak in common Japanese.
My brother lives in Tohoku and I’ve stayed there for about one month. I met many people who were about 25 years old there. They tried to speak in common Japanese to me but their Japanese was strange! When I heard they spoke each other, I didn’t understand what they talked about.
So I can’t imagine people in Okinawa speak in common Japanese.

“Wind” is “kaze” in Japanese and they pronounce it “kaji”.
It’s difficult to understand.　わかりにくいよねー！;)