Christina Aguilera and Jimmy Fallon surprise fans in NY subway

Christina Aguilera and Jimmy Fallon made surprise appearance in NYC subway.

Christina Aguilera surprised absolutely nobody when she tried to pull off a secret performance in a New York subway station on Wednesday that aired on The Tonight Show.

She and Jimmy Fallon went - or at least attempted to go - incognito for an impromptu show beneath the Big Apple.

The 37-year-old wore a long green skirt and short faded denim jacket, hiding her face beneath shades and a huge floppy hat.

Fallon wasn't that much better hidden beneath his long wig, fedora and round frame shades.