R&B Music Forum

Can somebody tell me the title of this rap/hip hop/rnb song?
I dont know the full lyrics of it but as far as i remember, the chorus has line where it goes some thing like:

"...young L...who did this beat?!..."

then it follows with a clever sounds again... it's cool!though I dunno the title...Till now Im craving for it....Please help!.....

Sorry, those are the lines I remember when I first heard it on radio... Any Idea? or Keyword for the title????