In the film 'Shall We Dance', Fred Astaire and Ginger Rogers tap dance together while wearing what on their feet?

'Shall We Dance', released in 1937, is the seventh of the ten Astaire-Rogers musical comedy films. The idea for the film originated in the studio's desire to exploit the successful formula created by Richard Rodgers and Lorenz Hart with their 1936 Broadway hit On Your Toes. The musical featured an American dancer getting involved with a touring Russian ballet company. In a major coup for RKO, Pan Berman managed to attract the Gershwins (George Gershwin who wrote the symphonic underscore and Ira Gershwin the lyrics) to score this, their second Hollywood musical after Delicious in 1931.

One of the films musical numbers is "Let's Call the Whole Thing Off". Astaire and Rogers sing alternate verses of this quickstep before embarking on a partnered comic tap dance on roller skates in a Central Park skating rink. Astaire uses the circular form of the rink to introduce a variation of the "oompah-trot" he and his sister Adele had made famous in vaudeville. In a further dig at ballet, the pair strike an arabesque pose just prior to toppling onto the grass.