Hans Christian Andersen's "The Emperor's New Clothes" (1837) is a fairy tale with no fairies in it, about two scoundrels who tell an Emperor that his new outfit will be invisible to people unfit for their position or impossibly stupid. They actually just pretend to make the new clothes, and dress him in nothing.
He struts about naked, with everyone afraid to say anything until a small boy points out "The Emperor has no clothes."
The phrase is often used to criticize yes-men who are afraid to point out their boss's flaws and mistakes. Such as, for instance, the Republican Congress telling the Orange Goblin, "It was a good thing that you said" every day for the last 18 months.
Writers who want to adapt "The Emperor's New Clothes" for the stage run into two problems:
1. The story is very short, with one-dimensional characters. It has to be extensively fleshed out.
2. You can't have a guy running around naked in a performance that will draw children.
They usually end up just making the Emperor a vain fashion-plate, and giving the plot to someone else. For instance, Alan Jay Friedman's musical adaption (1969) has a princess and a prince disguised as a commoner save the kingdom from villains exploiting the Emperor's love of haute couture.
Alan Schmuckler and David Holstein have a musical version where the Emperor and his daughter Sam learn to get along with each other through judicious costume choices.
Eric Coble has a Caribbean adaption: Jasmin wants to wear a simple sash, but the Emperor of the island requires fancy clothes. Until the magic tailor Buzz Butler arrives.
The Stephen Flaherty and Lynn Ahrens musical puts a gay-subtext take on the story. When 14-year old Marcus becomes emperor, he is uncertain how a wise ruler behaves. A Swindler offers to give him a magical suit that will allow him to know everything. His advisors are opposed to the idea, but he puts on the suit anyway, and everyone begins "yessing" him. Only Arno, the palace mop boy, turns out to be a true friend, and tells him the truth.
See also:
Hans Christian Andersen
