Will Smith: Imprompu Rap on 'David Letterman'!

Will Smith heads inside the Ed Sullivan theater to make an appearance on The Late Show with David Letterman on Monday (May 20) in New York City.

While making his entrance on the stage, the 44-year-old After Earth star did an impromptu rap – check it out below!

Will went on the program to promote his upcoming movie After Earth, which also stars his son Jaden Smith.

Jaden was spotted out in the Big Apple that same day carrying his skateboard in two different outfits.

After Earth hits theaters on May 31.

10+ pictures inside of Will and Jaden Smith in New York…