A person who always feels that they are on the cutting edge (eg- not yet released) of hip hop music. Like a hipster, but for hip hop. This includes rap, R&B, and hip hop. This person usually feels like they're better than most music listeners, even though they usually like crappy music (there is a reason it isn't popular).
A- Did you hear about B telling me about the new Chris Brown music?
C- Yeah, and it sounds terrible. He's such a hiphopster.