Gilbert and Sullivan operetta is a form of musical theatre that originated in the late 19th century. The most famous example of this genre is Iolanthe, an 8-letter operetta written by W.S. Gilbert and Arthur Sullivan. Iolanthe tells the story of a fairy who falls in love with a mortal man, and the comedic consequences that follow. It is known for its witty dialogue, memorable characters, and catchy music.