1) A Jamaican-sounding guy singing in broken English and making little if any sense
2) Any girl with a half-decent voice, usually singing about dancing in the club or something equally overused and pointless
Apparently some people in America actually like this kind of music and have the impressive self-restraint to avoid changing the station when such a group is on the radio. I have yet to meet such a person, but I'd guess that middle schools all over the country are full of them.
"Shake yo booty mama
Shake shake yo booty
I like to see you shake it
Shake yo booty shake it"
"I'm in the club dancing on a Friday night
I'm hangin with my peeps and I feel all right"
And so on...
The above song would probably crack the top 10 on the pop charts if I were to expand the lyrics and produce it. Sad, isn't it?