I think it's interesting how rap music has been appropriated by diverse people groups to express their oppression. "Feelin' Rezerved" by War Party is an example from my corner of the world (Alberta, Canada). The song has all the strengths of good rap--tight rhyme, word play, beat track--and a positive message. I can't say the same about the production value of the video, but it has some moments. Check it out.
"Feelin' Rezerved" War Party (video)
War Party has tons of their music plus more videos available for free download at their website.