Hustler is used a lot in rap. It's always been there. A hustler hustles. They put in work. They are in the grind. It's all about turning a nickel into a dime. In other words, they sell a lot of crack. Nothing deep.
https://www.youtube.com/watch?v=xZbwTCrnktY - Cassidy - I'm a hustler
https://www.youtube.com/watch?v=sv6CbP4kVno - Lil Wayne - Hustler Muzic