MUSIC: Castle Walls (prod. Alex Da Kid) (feat. Christina Aguilera) - T.I.

From the producer of Eminem's "Love the Way You Lie" and B.o.B.'s "Airplanes," Alex Da Kid drops off another dope track. This time for T.I. & Christina Aguilera. Sounds like Alex Da Kid has another hit. No Mercy drops December 7th.