Trivia: To make the effects of Audrey II look convincing, the animatronic was usually shot at a lower frame-rate, such as 12 frames per second, and then played back at the standard 24fps. This sped-up the shots and made the animatronic's motions look more fluid and lifelike. In order to compensate, whenever a human actor would be in-shot with Audrey II, they would have to act in "slow motion" in order for their movement to look right at 24fps. (You can kinda tell in a few shots if you look closely).
Trivia: It was during the filming that Elvis first heard of The Beatles when someone had their first English LP on the set. He took it into his room and listened to it for hours. He then banned their music from the set.
Trivia: The voice for the animated Popeye was done by Jack Mercer who provided the voice for the Popeye the Sailor cartoons.
Trivia: The large engagement ring that Grace Kelly wears in the movie is not a prop. It was a real 10-carat diamond engagement ring given to Kelly by her fiancé and later husband, Prince Rainier of Monaco.
Trivia: SPOILERS: Director Todd Phillips has defended the controversial ending, in which it is revealed that Arthur is not the Joker who would go on to fight Batman when he is stabbed and killed by another inmate, who then carves a smile onto his face. Phillips noted that the two films were called "Joker," and not "THE Joker," and stated that Arthur was the person who inspired the real Joker—presumably the inmate who killed him. However, this explanation was poorly received by fans, who felt duped.
Trivia: During the title sequence, as Millie is buying a pack of cigarettes from a vendor, her undergarment breaks. The vendor stares at her in surprise, and she does a slight curtsy and walks away. When the film was originally released, that was followed by a quick shot of the vendor looking down and seeing Millie's broken undergarment lying on the sidewalk, but for some unknown reason, that shot has been deleted.
Trivia: Audrey Landers is not seen in wide shots of the entire cast while dancing because she was an inexperienced dancer.
Trivia: 1980s teen idol Tiffany provided the voice of Judy Jetson. She also provided the songs found in the film. To her dismay, critics not only attacked the film, but the songs she sang.
Trivia: The Holiday Inn chain of motels, founded after World War II was named after this movie, not the other way around.
Trivia: Shirley Jones was pregnant during the movie. She wore a special corset to conceal this. Director Morton DaCosta did not want anyone else involved in the movie to be aware of her pregnancy. He was so successful, that it was not until the kissing scene on the bridge that Robert Preston (Harold Hill) found out, when he was shocked to feel Jones' baby kicking him in the stomach.
Trivia: When Robin Hood and all of the villagers are having the party and singing and dancing, look closely at the dance, it's from Snow White. Some of the villagers are the dwarfs and Maid Marion is Snow White. Also, when Little John is dancing it's from The Jungle Book.
Trivia: Adam Sandler's wife, Jackie Titone, was the voice of Jennifer.
