T.I. and Christina Aguilera

T.I. explains the difficulties of living in the limelight on the somber “Castle Walls,” the latest single from No Mercy (Dec. 7). Produced by Alex Da Kid and co-written by his artist Skylar Grey, the track features a haunting instrumental over which Christina Aguilera sings a touching chorus.

“Everyone thinks that I have it all/ But it’s so empty, living behind these castle walls, these castle walls/ If I should tumble, if I should fall/ Would anyone hear me, screaming behind these castle walls/ There’s no one here at all/ Behind these castle walls.”

Listen to Xtina’s part on the 30-second snippet below.