The new biopic stars Timothée Chalamet as the musical genius, but it’s less about him than about his effect on others.

The new Bob Dylan biopic, “A Complete Unknown,” hits movie theaters on Christmas Day. It’s already considered a leading contender to land Oscar nominations for Best Picture and Best Actor, with Timothée Chalamet winning raves for his performance as a young Bob Dylan.

One of the most suspenseful movie scenes of the year isn’t a stunt or plot twist. It’s the quiet moment when Timothée Chalamet first reveals if he can actually channel Bob Dylan. It happens early in “A Complete Unknown,” starring Chalamet as ...