It’s a familiar story: Someone goes to a Broadway musical, ignores the audience rules of conduct and pulls out a phone.

But on Monday night, that someone was Kanye West, the musical was “The Cher Show,” and it was the glittery and bespangled opening night.

The performance had been underway for about an hour when the actor playing Sonny Bono, Jarrod Spector, took to Twitter to call out Mr. West’s behavior.