Said at the risk of being perceived as racist, the form of English spoken by many Rappers differs quite a bit from that of Anglos in the U.S. of A. Not quite a different language, but pretty darn close. I axed (;-) my sister why that is (her daughter has a half-white, half-black daughter, and two 3/4's black, 1/4 white granddaughters), and she said it's a cultural thing.
When I was in London in 1982, I went to a large farmer's market on a Sunday morning. I was amazed by how many different British accents I heard---some of them completely unrecognizable as being of the English language, and amused to hear the British blacks speaking with some of them.