An actor down on his luck gets an unexpected call one morning from his agent. “Listen,” he says, “I have an opportunity for you. A producer just called me; one of his actors got a part in another show, and he needs somebody starting tonight. It’s just one line, but it’s an important one. You walk out at the beginning of the play, and you say, ‘Hark, I hear the cannon’s roar!’ You think you can handle that?”
“Of course! Thank you! This is fantastic!” the actor replies.
“Great, kid. Be at the Shubert at 6:30 tonight for call.”
So all day, the actor keeps repeating to himself, “Hark, I hear the cannon’s roar!” He repeats the line over and over again, during lunch, during dinner, taking a shower, in the cab ride on the way to the theater.
Once in costume and makeup, the actor paces back and forth backstage, all the while repeating to himself, “Hark, I hear the cannon’s roar!” The stage manager calls the cast to places, and the actor eagerly awaits his entrance.
The curtain rises, the lights come up, and the actor walks confidently out on stage. As he does, the mighty BOOM of a cannon thunders through the theater.
In response, the actor jumps and yells out, “What the hell was that?”