Three years ago, when Disney announced a remake of its animated classic The Lion King, it was easy to be skeptical: With the original still so beloved, was an upgrade even necessary? But at least one family in South Africa was hopeful. In both the first movie and a later stage production, The Lion King features “The Lion Sleeps Tonight,” a Sixties pop hit that has its roots in “Mbube,” a song written and recorded in the Thirties by South African singer and migrant worker Solomon Linda. For decades, Linda...