Answer:
In The Pirates of Penzance, mistaken identity plays a significant role in the plot and creates a series of comic consequences. Frederic, the protagonist, is mistakenly indentured to the pirates as a young child, leading to his confusion about his true identity. The pirates, on the other hand, mistake the Major General for a fellow pirate and attempt to kidnap him, causing chaos and hilarity. Meanwhile, the Major General and his daughters are mistaken for a group of professional musicians, leading to their humorous attempts to perform. These mistaken identities add a layer of comedy to the already whimsical and absurd plot of the operetta.