Fred Astaire was the favorite singer of Irving Berlin, Cole Porter and the Gershwins. Why was this dancer so beloved by these composers? That question launches Feinstein into an exploration of the marriage of music and choreography, unearthing rare home movies of Astaire rehearsing on set, and never-before-seen footage of Gene Kelly's Broadway debut in the original Pal Joey. Liza Minnelli, who knew both Astaire and Kelly, dispatches an amazing deconstruction of a dance number from the musical perspective. Feinstein explores the popularity of ballroom dance in America and performs "Singin' in the Rain" and "Let's Dance."