Christina Aguilera and Jimmy Fallon disguise themselves to busk in public

She has one of the most recognisable voices in the world, but many people didn't even recognise her when Christina Aguilera performed on a New York subway.

The star, along with talk show host Jimmy Fallon, dressed up in full disguise to surprise subway goers with a performance.

The video of Christina and Jimmy has been viewed millions of times in just a few days. Check it out above!