Documentary film, "Defiant Requiem," written and directed by Doug Shultz, 2013

From https://www.defiantrequiem.org/film/description/ (accessed Feb. 28, 2022):

Defiant Requiem, a feature-length documentary film, highlights the most dramatic example of intellectual and artistic courage in the Theresienstadt (Terezín) Concentration Camp during World War II: the remarkable story of Rafael Schächter, a brilliant, young Czech conductor who was arrested and sent to Terezín in 1941. He demonstrated moral leadership under the most brutal circumstances, determined to sustain courage and hope for his fellow prisoners by enriching their souls through great music. His most extraordinary act was to recruit 150 prisoners and teach them Verdi’s Requiem by rote in a dank cellar using a single score, over multiple rehearsals, and after grueling days of forced labor. The Requiem was performed on 16 occasions for fellow prisoners. The last, most infamous performance occurred on June 23, 1944 before high-ranking SS officers from Berlin and the International Red Cross to support the charade that the prisoners were treated well and flourishing.

With testimony provided by surviving members of Schächter’s choir, soaring concert footage, cinematic dramatizations, and evocative animation, this unique film explores the singers’ view of the Verdi as a work of defiance and resistance against the Nazis. The text of the Requiem Mass enabled them, as Schächter told the chorus, to “sing to the Nazis what they could not say to them.”