An 11 o’clock number is a big, show-stopping song that typically occurs late in a musical—usually in the second act, near the end of the show (around 11:00 PM in traditional curtain times). This number is often delivered by the protagonist or a key character and marks a moment of major realization, transformation, or emotional climax. It serves to re-engage the audience before the finale and is often one of the most memorable songs in the production. Examples include “Rose’s Turn” from Gypsy and “Memory” from Cats.