Actor and singer Will Smith surprised fans at the London premiere of his latest film I, Robot by putting on an impromptu concert.
Will Smith delighted fans with his vocal performance
The 35-year-old star, accompanied by DJ Jazzy Jeff, sang hits including Men In Black and Summertime on a temporary stage in London's Leicester Square.
"I wanted to give the people who came to support me a little treat out here," said Hollywood star Smith.
He plays a detective in the sci-fi film which opens in the UK on Friday.
Smith also performed his new single Switch, which appears on the I, Robot soundtrack.
"There is nothing like being on stage with music," Smith told a US TV reporter at the premiere.
"You know as an actor I am more a tool for the director to see his or her vision, but as a musician I write what I want to write and say what I want to say."
The actor is due to his release a new album later this year.
The futuristic thriller, set in Chicago in 2035 and based on an Isaac Asimov novella, depicts a world where robots are part of everyday life.
"Science has always been a huge part of my life. From five years old I wanted to be a scientist," said Smith.
"When I got to 11 or 12 years old I got interested in entertainment. So being in a sci-fi film is a perfect blend of the two," he added.
Also at the UK premiere were members of the boy band Busted and Baywatch star David Hasselhoff.
I, Robot took $53.3m (£28.4m) in its opening weekend in the US last month, making it Smith's best debut, despite turns in blockbuster hits Men in Black and Independence Day.