She died in September, putting Astaire in a state of grief and stalling his work on the film. Although replacements were sought for Astaire's role, as too much money had already been spent on the production, he resumed and completed the film. Key songs/dance routines Astaire had previously attempted to integrate ballet into his dance routines in Shall We Dance (1937). As his first film in Cinemascope widescreen–which he was to parody later in the "Stereophonic Sound" number from Silk Stockings (1957)–Daddy Long Legs provided Astaire the opportunity to explore the additional space available, with the help of his assistant choreographer Dave Robel. Roland Petit designed the much-maligned "Nightmare Ballet" number. As usual, Astaire adapted his choreography to the particular strengths of his partner, in this case ballet. Even so, Caron ran into some problems making the film, her last dance musical, which she attributed to her early musical training. Astaire mentioned in his biography that "one day at rehearsals I asked her to listen extra carefully to the music, so as to keep in time." "History of the Beat": This is an Astaire song-and-dance solo using drumsticks performed in an office environment, recalling the "Nice Work If You Can Get It" routine from A Damsel in Distress (1937) and the "Drum Crazy" number from Easter Parade (1948). As this was the first number to be filmed, some commentators have speculated that it was affected by Astaire's grief at his wife's death. "Daddy Long Legs": An off-screen female chorus sings this attractive number while Caron muses fondly at a blackboard cartoon sketch of Astaire. "Daydream Sequence": Astaire appears in three guises: a Texan, an international playboy and a guardian angel based on images of him described in letters from Caron. As a Texan, he performs a comic square-dance routine to a short song dubbed by Thurl Ravenscroft, the only time in his career that Astaire's voice was dubbed. As an international playboy, he tangoes his way through a flock of women, including Barrie Chase, later to be his dance partner in all of his television specials from 1958 to 1968. The third routine is a gentle romantic dance with Caron, who performs graceful ballet steps while Astaire glides admiringly around her. "Sluefoot": This is a boisterous and joyous dance with Astaire and Caron involving sharp leg movements. Astaire inserts a short and zany solo segment, and the chorus join in