The Broadway version uses the original 1944 score by Leonard Bernstein, Betty Comden and Adolph Green, but the 1949 movie substituted several songs by others. In this clip, the song "Main Street" was written by Roger Edens, Comden and Green. The choreography in the film is credited to Gene Kelly.
The clip is introduced by the show's star, Tony Yazbeck, who speaks of his admiration for Kelly, whose role he is playing.
At the 2:22 mark the screen splits so you can see the 1949 film dancers on the left and the 2015 Broadway dancers on the right, performing exactly the same steps.