"Big" starring Tom Hanks
FAO Schwarz, 5th Avenue & 58th Street, New York City
In one of the movie's most memorable scenes, Josh runs into his boss, the owner of MacMillan Toys, who spends his Saturdays at FAQ Schwarz observing what toys kids are into. He and Josh spend a little time bonding as Josh explains his likes and dislikes of various toys (much to the bemusement of Mr. MacMillan). They stumble about a large floor model "piano," where Josh starts to play "Heart and Soul." Mr. MacMillan joins in, and together they do a well-coordinated routine consisting of Heart and Soul and Chopsticks. Having not had so much fun in a while, MacMillan taps into Josh's knowledge of toys and makes him vice president....one of them, anyway - they have a hundred of them!
*Screenshot from the movie used for comparison to a photo of me taken at the same location (navigate two more photos to the right in my set, "Other Filming Locations")