Claim: The show business phrase "The show must go on", originating in the 19th century, means that the show must be performed, regardless of what else happens.
Evidence: "The show must go on" is a phrase in show business, meaning that regardless of what happens, whatever show has been planned still has to be staged for the waiting patrons. The saying and principle are traditional in the theater, but they both originated in the 19th century with circuses.