The movie I'm thinking of I watched about 4+ years ago and about twin brothers that were rap artists.One bro was killed in an alley after a gig and the surviving bro has the guilts because he set up the mugging which ended with his brother dying.During the film the surviving bro is waiting with his manager at a train station and they are arguing about rap not being a real.To prove his point the rapper went on to rap along with the classical music that was being played over the pa system. Until I saw that scene I would have agreed that rap isn't music but just noise but to hear someone rapping to mozart was an experience that stuck with me and now I happily enjoy good rap artists when ever I can.But the name of that movie alludes me.The actors looked maybe mexican/american or possibly african/american and aged in their mid-late teens.Hope my vague memory of the plot helps someone to help me name the movie finally.