The Beatles star shocked guests attending Russian billionaire Roman Abramovich's exclusive New Year's Eve party on the Caribbean island of St. Barts on Saturday when he joined frontman Brandon Flowers and his bandmates onstage.

Video footage posted on Twitter shows MCCartney taking to the stage as the crowd cheers. He tells them, "Happy new year," before acknowledging their surprise by mockingly exclaiming, "What is going on?!" before he begins singing the Beatles' hit Helter Skelter.

The Killers also shared a clip on their Facebook page and wrote in the caption, "So far, so good."

On Sunday (01Jan17), MCCartney wrote on Twitter, “Happy New Year’s Day. May this year be a happy and peaceful one for you and your family and everyone around the world. Love Paul.”