When a poor, imaginative young girl named Mary Calhoun wishes she could play her violin, her mouseling dolls, Angelina Mouseling and her best friend, Alice Nimbletoes and her dog, Dodger, realize her dreams to come true. But the next morning, when she makes them come to life, they decide to move to New York City to put on a big surprise birthday show for her dad at the fair called the Hoop-Dee-Doo! Musical Revue. When they arrive there, they invite their friends, hand out their invitations, and they go on a tour of the city and the New York World's Fair and check into a big grand hotel, but they have to get rid of the three tomcats, Meowcent, Jinkquade and Aldoof and stop them from taking on revenge of the city. During rehearsals, they pick out fancy clothes and costumes for the main show at the Broadway Theatre, perform dances, sing songs, recite nursery rhymes and make up stories. Later, they make their dad's birthday show a big reality with the mouselings singing and dancing and Mary playing her violin while Martha and Dodger watch them perform. This adventure is about the importance of teamwork to get the job done through life and curiosity.
