Hip hop music can give you an insight into life in the ghetto in America. The stories I hear in rap are like crime novels or gangster movies for me. In the case of someone like Jay Z who apparently used to live a gangster life music did help him to escape the world of crime. Hip hop slang crops up everywhere and it's sort of very very influential now. Also the English that you're here in this hip hop track is to an extent a dialect. It's kind of like the language of black American youth  and this is one of the most pervasive English dialects.