Act One: The Storm
A young girl named Dorothy Gale lives on the great Kansas prairie with her Aunt Em, Uncle Henry, and cow, Imogene. One day, while she is playing with her pet cow, Imogene, a fierce whirlwind appears. Dorothy and Imogene take shelter in the farmhouse, which is carried far away into the clouds.

Meanwhile, in the hamlet of Center Munch, the little Munchkins dance around their maypole, not noticing that Dorothy's house has fallen to Earth and killed the Wicked Witch of the East. Dorothy opens the front door and marvels at the strange Land of Oz. The Good Witch of the North awards her with a magic ring that grants her three wishes and can summon Glinda the Good Witch of the South at any time. The Good Witch then waves her wand and a pair of beautiful shoes appear on Dorothy's feet. She tells Dorothy that if she wants to get home, she must ask the Wizard of Oz to help her.

After a while everyone exits, and Dorothy is left alone with a Scarecrow hung on a pole. She wishes she had someone to talk to, and he comes to life. He gets down from the pole and complains that he has no brain. Dorothy suggests that he join her on the road to the Emerald City, and he sings "Alas for the Man Without Brains." They come upon the Tin Woodman, who has rusted playing his piccolo. As it turns out, his real name is Niccolo Chopper. He explains that the Wicked Witch of the West took his heart, so he cannot love his girlfriend, Cynthia. He joins them in the hope of receiving a heart from the Wizard, so that he can return to Cynthia.

Act Two: The Emerald City
The Keeper of the Gates patrols outside the Emerald City. Sir Wiley Gyle enters, a mad old inventor who has scorned magic since his mother died. He is sent to prison for murdering his wife. The travelers enter the Emerald City.

The Wizard gives the Scarecrow a brain and the Tin Woodman a heart. He declares this the greatest of all his achievements and calls for a celebration. The Ball of All Nations is thrown, in which up to twelve songs are sung by various characters. The Wizard performs a basket trick in which King Pastoria is the mark. In the middle of it Pastoria claims his right to the throne and overthrows the Wizard. A great commotion breaks out, with the Wizard escaping in a hot air balloon. Dorothy, still longing to get home, sets off with her companions to the castle of Glinda, the Good Witch of the South.

Act Three: Glinda's Palace
Dorothy and her friends arrive at Glinda's palace and are welcomed. There are great celebrations, with Glinda promising to send Dorothy home. The whole cast rushes out from the wings and sings the finale.