Carol Reed supervises Anton Karas who provided the entire musical score for the film, The Third Man, with this one instrument, the zither.
The "Harry Lime Theme" sold over half a million copies in its first month and made Karas a star but alas, his popularity was not to last. He was unpopular in his home of Vienna because he had gained his success with a film that portrayed a defeated, divided Vienna. Geez. And every follow-up he did essentially flopped. But he had that one song and it was enough that he could retire a millionaire. If you'd like to read up on the whole story of Karas and how Reed stumbled across him here's a nice bio from allmusic.com.
This post was originally run in August of last year but for those who didn't see it then I figured now was as good a time as any to run it again.