Korean Pop Culture

I can't think of nothing but young idol groups. I don't remember since when cute, beautiful, and sexy girls and tall, pretty, and well-built boys swept the stage. I asked several people around me, "What comes to you first when you think of Korean pop culture?" All the men's answers were "Girl Generation"
What's the required talent of the singers? Powerful voice, outstanding singing ability, or attractive looks?
Kids and teenagers are crazy about the young idol groups. When I ask my students why they liked them, almost everyone said, they're cute, pretty, handsome, and cool.  Good looking apprearance is everything. What about the music?