"Once Upon a Mattress" is a musical comedy that retells the classic fairy tale of "The Princess and the Pea." The story follows Princess Winnifred, a spirited young woman who wants to marry Prince Dauntless. However, she must pass a test set by the overbearing Queen Aggravain to prove her royal status. The musical features catchy songs and humorous situations as Winnifred navigates the challenges posed by the queen. With themes of love, identity, and the quest for acceptance, "Once Upon a Mattress" offers a lighthearted twist on traditional fairy tales, making it enjoyable for audiences of all ages.