She's not coming back to The Voice for season four, but Christina Aguilera made a jaw-dropping comeback anyway at an event for the NBC reality show on Wednesday, March 20, 2013. Making a surprise appearance on the red carpet for the season-four premiere screening at the TCL Chinese Theater in L.A., the "Your Body" singer, turned heads in a little black-and-white dress that showed off a noticeably slimmer figure -- not to mention Aguilera's toned, sexy legs, accentuated by high Louboutin heels.