The music played at the end by the Jewish prisoners is Gustav Mahler's first symphony, third movement. This movement uses as one of its themes a parody of the popular children song "Frère Jacques", and the whole symphony borrows heavily from one of Mahler's song cycles, Lieder eines Fahrenden Gesellen. The last song, "Die zwei blauen Augen" (The two blue eyes) can be heard sometimes during the movie, as in the end of the movie shoot and as part of the symphony's movement being played.
In the scene, when Halder takes a walk with his ex-wife in the cemetery, which is supposed to be in Berlin, Germany, Hungarian names are clearly visible on the gravestones.