If you'd like to see how the Japanese handle Western-style popular music and dancing, you'll find good quality jazz clubs, conventional discos (with, naturally, fantastic electronic equipment), and even country-and-western saloons, all in Tokyo's cosmopolitan restaurant districts of Akasaka and Roppongi.
Akasaka and Roppongi in Tokyo are good places to observe the way Japanese people interpret Western-style music and dance.