Early 2000's song, children singing the chorus, pop/hip hop
I've seen the music video, I think twice, by coincidence, a few years ago, it features/is performed by a very well known hip hop/rap group (of which name, I can't remember, but at the time, I was like "Oh they made this?", it has a very catchy base line and I think the kids just simply sing "La la la laa" or something like that in the chorus.
I think the video was shot in doors, it's pretty darkly lit, but kind of colorful. It's a very positive song that makes me think of innocent parties of the summer (if that makes any sense)
(I'm not sure if the verses were rapped or sung, but I'm pretty sure it was a male, from the group)