When the Power Goes Out on Stage, Performers Turn to Improv

JOHANNESBURG—Sue Diepeveen was acting on stage in her original one-woman play when the power went out, plunging the red-velvet-lined theater into darkness. It wasn’t the showstopper she was hoping for.

“‘Oh, my God, I’m sure that I paid this bill,’” she recalled ad-libbing at Johannesburg’s Theatre on the Square. And she quietly thanked her lucky stars that the outage—on opening night in September—came right after she had delivered some lines about her character’s money troubles. “I actually got quite a few laughs.”