* DawsonCasting: Harold Hill's actual age is never explicitly stated, but he makes claims to have graduated from Gary Conservatory in 1905, seven years prior to the events of the story. Even though this is a lie, the fact that people believe it provides insight into his actual age. A conservatory graduate would usually be the same age as a college graduate, or about 22, making Hill approximately 29 years old. Robert Preston was 39 when he played the role on Broadway, and 44 in the movie. Matthew Broderick was also 41 when in the 2003 version.
* DevelopmentHell: The producers of the live musicals Creator/{{NBC}} started airing during TheNewTens announced ''The Music Man'' as a possible choice for 2015's musical, until they decided to adapt ''Theatre/TheWiz'' instead. However, after ''The Wiz'' aired, the producers did admit the possibility of NBC broadcasting ''The Music Man'' in a different year.
* ExecutiveMeddling:
** Semi-averted. The studio wanted a new star for the film but Willson refused. Astounding when you consider Preston had already won a Tony for the role. However, the studio did manage to get their way with Buddy Hackett and Shirley Jones.
** Played straight in the fact that Meredith Willson wanted the movie to be shot on location (Mason City, IA), particularly at the library. Due to budget reasons, the film was instead shot in Hollywood and as a consolation, the world premiere was held in Mason City.
* HideYourPregnancy: The movie had to shoot around Shirley Jones's pregnancy, getting as many full-body shots out of the way as quickly as they could before she began to show. When she and Robert Preston filmed "Till There Was You," on one take he accidentally bumped into her... well, bump, asking "What was that?" to which she replied "My son." Years later, Preston was introduced to Jones's then-grown son and joked that they had already met.
* ThrowItIn: "Rock Island" was not originally conceived an an a capella piece. During rehearsals for the original production, the accompanist was late one day, forcing the actors to sing it as such. Everyone liked it enough to keep it that way.
* TropeNamers: WithACapitalT
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