Timothée Chalamet portrays Bob Dylan in James Mangold’s “A Complete Unknown,” a rhythmic biopic unpacking his rise to rock ’n’ roll stardom. The spark behind his musical journey is the “Freewheelin’” singer’s decision to uproot from his Minnesota hometown for New York to play a song he wrote for folk icon Woody Guthrie, who lies unwell in a hospital. Cinematographer …
