It's quite possible that you forgot about "Tilt Ya Head Back" — the No. 58 Billboard Hot 100 chart-middling smash of 2004 by "Hot In Herre" hitmaker Nelly and Christina Aguilera — until just now.

Britney Spears, pictured here at a Christmas tree-lighting ceremony on Nov. 21, 2015, in Las Vegas, was originally supposed sing on Nelly's 2004 hit "Tilt Ya Head Back." Getty Images Nelly and ...

Nelly – “Tilt Ya Head Back,” feat. Christina Aguilera. The key to a good collaboration is making sure that all artists involved get to show off their best parts.

And there’s maybe a reason why it sounds like X-Tina. In 2004, Nelly released the song “Tilt Ya Head Back,” featuring vocals by Christina Aguilera.

”Tilt Ya Head Back,” from Nelly’s Sweat (2004) Before the Baby Jane alter ego fully emerged on Aguilera’s just-released Back to Basics CD (and its lead single, ”Ain’t No Other Man ...

This song was featured on Diddy's 2006 album Press Play, but I need to hit rewind because my recollection of this collaboration is rather foggy. "Tilt Ya Head Back" With Nelly ...