not quite Broadway, but up the street a bit at the Metropolitan --
Laurenz Melchior was singing the lead in LOHENGRIN one night -- final act, when he leaves his wife and returns to God only knows where. At any rate, he's supposed to leave in this famous swan boat. That particular night, the swan was pulled off stage by an inattentive stage hand. Melchior didn't notice till the end of his final aria, looks, sees no swan, turns back to the audience and says, "Excuse me, does anyone know what time the next swan leaves?"
"That duck was a sexual toy, and it was on display!" -- an unknown Nashville town leader