The first cartoon selected for the National Film Registry.
Warner Bros. Cartoons, Inc. only allotted five weeks for the production of each seven-minute short, but director Chuck Jones spent seven weeks on this short. To cover up for the extra time spent, he had his entire unit doctor their time cards to make it appear as if they working on the Road Runner/Coyote short Zoom and Bored (1957) for two weeks before they actually started (since Chuck and his staff were so familiar with the Road Runner formula, they were able to complete Zoom and Bored in three weeks).
According to Chuck Jones, there are 104 cuts in this cartoon, an unusually high number for a Warner Bros. cartoon.
For the ballet scenes, Chuck Jones and his animators studied dancers Tatiana Riabouchinska and David Lichine, who were working for Warner Bros. at the time. Both dancers had previously worked on Fantasia (1940), as reference models for the "Dance of the Hours" sequence.
In animation historian Jerry Beck's 1994 poll of animators, film historians and directors, this cartoon was selected as the #1 cartoon of all time.