Debuting on this day in the UFA Palast am Zoo in Berlin in 1931, the film M by Fritz Lang (previously here and here) and co-written by Lang and his wife Thea von Harbou was the director’s first sound motion picture and includes innovations like tracking shots and a leitmotif in the form of eerie whistling of Edvard Grieg’s “In the Hall of the Mountain King—” done by Lang as Peter Lorre could not carry a tune. The plot, criticised initially for being too long at one-hundred fourteen minutes, is the prototypically noir police procedural and “courtroom” drama (apprehended and tried by his peers) about the capture and trial of a serial killer of children and is counted among the greatest cinematic works of all time. Lang himself considered it to be his magnum opus with pointed social commentary for his adopted homeland of Germany, which he reviled for allowing Nazism to take root. Auf die Kinder muss man besser aufpassen… Sie alle!