Watch Will Smith's Impromptu Performance

Watch Will Smith hark back to his musical days with a brilliant rendition of his track Summertime on the David Letterman Show.

The 44-year-old made his name as a rapper before becoming one of the biggest names in Hollywood.

Dressed in a satin blue suit, Will looked every inch The Fresh Prince of Bel Air.

Smith was a guest on the chat show to promote his new film After Earth, in which his 14-year-old son Jaden also stars.

Watch the video below: