Top hat ribs and springs. His patent was described as: Some sources have taken this to describe an early folding top hat, although it is not explicitly stated whether Dollman's design was specifically for male or female headgear. Dollman's patent expired in 1825. In France, around 1840, Antoine Gibus's design for a spring-loaded collapsible top-hat proved so popular that hats made to it became known as "gibus". They were also often called "opera hats" due to the common practice of storing them in their flattened state under one's seat at the opera, though the term can also refer to any tall formal
Top Hat as early as 1915. There ensued a lifelong friendship with Berlin contributing to more Astaire films (six in total) than any other composer. Of his experience with Astaire in "Top Hat" Berlin wrote: "He's a real inspiration for a writer. I'd never have written "Top Hat" without him. He makes you feel so secure." As Berlin could not read or write music, and could only pick out tunes on a specially designed piano that transposed keys automatically, he required an assistant to make up his piano parts. Hal Borne – Astaire's rehearsal pianist – performed this role in "Top Hat"