Hollywood musicals were wildly popular during the 1950s and ’60s, and three actresses in particular—Audrey Hepburn, Natalie Wood, and Deborah Kerr—thrilled viewers with their compelling performances. But a huge part of the appeal of these actresses was the breathtaking singing that enhanced their acting. In fact, the classic films’ successes were actually due in large part to Marni Nixon, who dubbed the voices for each of those leading ladies and who for a long time went completely uncredited for her vital contribution.

In the body of Christ there are often people that faithfully support others who take a more public role.…