One of the most daring musical choices in cinema history occurred in the noir classic 'The Third Man.' Director Carol Reed decided to forgo a traditional orchestra, instead hiring a local Viennese zither player named Anton Karas. The zither is a flat, stringed instrument common in Alpine folk music. Karas’s 'Harry Lime Theme' became a global sensation, topping the charts and making the zither an unlikely movie legend in its own right. The twanging, rhythmic sound of the instrument perfectly captured the tension and post-war decay of Vienna. Orson Welles, who played the legendary Harry Lime, was reportedly thrilled by the score’s unique texture. This remains a prime example of how a single, specific instrument can define the entire atmosphere of a legendary film performance.