Professional cellist Sophie Kauer had no prior acting experience and auditioned at the encouragement of a friend. She learned to act by watching YouTube tutorials hosted by Michael Caine.
Cate Blanchett had to re-learn the piano, learned how to speak German, and learned how to conduct an orchestra for the film.
The screams Lydia hears when jogging in the woods are the audio of Heather Donahue from the climax of Le projet Blair (1999).
The entire scene of Lydia teaching students at Juilliard is filmed in a single take of ten minutes and twenty-five seconds.
Todd Field wrote the film specifically for Cate Blanchett and would not have made the film without her. They had previously planned to work on a different film, but Field could not acquire adequate financing for it.