i need to know who sings this and what the song is please

hi, i live in Atlanta and I just heard this song on the radio for the first time tonight. It is a rap song. Pretty hard rap with a good melody and beat. The chorus then slows down and the guy says slowly,
back and forth, back and forth (or it actually might be) front to back, front to back,

and then it speeds up again. i know it isnt much but if anyone knows what I am talking about lemme know! thanks

because of: http://www.allthelyrics.com/forum/id...ng-please.html
I lock this here.