Miley: Yep! In the early Hannah Montana era
But as herself? Can't remember
Well except that performance Kaleidoscope mentioned.
But anyway YES she's done it!
Demi: I dont think so
Selena: I dont know. The So Random performance seems lypsynced but it could be a voice-over made by Disney for the TV broadcast like they did it for the Hannah Montana Season 3 Music videos... (I hate disney for doing this f*cking voice overs
)