Onstage, the first act was a duet: an elderly couple who’d been married fifty years, swaying as if the years were a slow, forgiving tide. They called themselves Avil & Hot—two nicknames their grandchildren used when teasing them about their summer romance—and they performed a gentle, improvised sea shanty that made half the audience wipe their eyes. The judges—an ex-lifeguard, a hairstylist, a woman who ran a dog grooming salon—scribbled notes and laughed when a seagull tried to join in.