Prosecutors have asked a judge to allow them to use the lyrics at the trial of Ronald "Da Riggs" Herron. Federal jury selection began Tuesday in Brooklyn.
The government says gritty recordings by Herron bolster allegations he was a stone-cold killer. One is titled "Live by the Gun, Die by the Gun."
Defense lawyers have argued that their client's work is a constitutionally protected expression of free speech that has no place in the case.
They compare it to Johnny Cash singing in "Folsom Prison Blues" that he "shot a man in Reno just to watch him die."