When Mac Wells was taping an audition for a role on the CMT drama series “Nashville,” he wanted to stand out among the other actors. To convey mischievous skepticism, he borrowed a move from Dwayne “The Rock” Johnson and raised his left eyebrow.
Mr. Wells got the part—a member of a church choir who is dubious about collaborating with a sexy pop star. That audition, back in 2016, was the first time his eyebrow acting “was really, really useful,” Mr. Wells says. “The eyebrow can have its perks.” Mr. Wells has a role in Mr....