The music played at the end by the Jewish prisoners is
Gustav Mahler's first symphony, third movement. This movement uses as one of it's 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.
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