Seen in the context of “Oppenheimer,” Steve James’ film serves as a fascinating complement—and in some ways, a corrective—to Christopher Nolan’s blockbuster.

Seen in the context of “Oppenheimer,” Steve James’ film serves as a fascinating complement—and in some ways, a corrective—to Christopher Nolan’s blockbuster.
In Jim Cartwright’s “The Rise and Fall of the Little Voice,” the struggling title character …