An N.W.A. reunion track
The last time Ice Cube, Dr. Dre and MC Ren collaborated was 2000, the last song released under the N.W.A. name dropped in 1999, and the last time all five surviving original members (Cube, Dre, Ren, DJ Yella and Arabian Prince) appeared on tracks together was the actual Straight Outta Compton album, released in 1988. Because Prince left the group just after their breakout album, getting him back into the fold seems unlikely, but if the rest of the guys were able to settle their past squabbles to help out with the movie, getting them in the studio shouldn't be too much of a struggle.
With guest appearances from Eminem and Kendrick, Dre is clearly trying to keep this thing a bit younger and fresher, but one reunion cut couldn't hurt as long as the beat's right.