NewYork: Actor Will Smith surprised a crowd of about 1,000 extras, who had gathered on the set of his movie “I am A Legend”, by performing an impromptu rap.

The extras were present for a scene and it was very cold. So Smith grabbed a mike from the assistant director and launched into a rap rendition of his hit song “Summertime”. Pagesix.com quoted an actress as saying: “More than 1,000 extras sang along at the chorus. It was a pretty great moment — everyone was definitely warmed up by it.” In the movie Smith plays the last uninfected man on a planet full of vampires.