 Many members of the original Broadway cast, including William Daniels, Ken Howard, John Cullum, and Howard Da Silva, reprised their roles for the film.Ralston Hill, Ron Holgate, David Ford, Charles Rule and others repeated their roles from the Broadway production, marking their only appearances in feature film.This was a decision Warner made himself after feeling he made a mistake by turning down Julie Andrews for the 1964 film adaptation of "My Fair Lady" in favor of Audrey Hepburn.