So you're almost at the end of the show, and things are looking very uncertain. But you know the show's about to end. That's when you know this trope is about to kick in. The Eleven O'Clock Number is a song in a musical placed near the end of the second act, before the plot's loose ends are tied up. The song usually represents an emotional turning point or revelation for the main character(s) and is almost always the last number in the show that isn't a reprise of an earlier song or the absolute final song. The term is a holdover from the days when all musicals started at 8:30 PM and had to have a climactic song around 11:00, because it was preferable to have audiences out shortly afterwards.