DA Pennebaker's First Film (don't worry, it's only five minutes long).
Lots of people think fine art and experimental work exists in opposition to documentary work, opposed in style, substance, and intent. Nonsense. DA Pennebaker, who recently passed, produced as his first film in 1953 a five minute short on and about the soon-to-be-demolished Third Avenue elevated train line, a piece that makes it easy to see how his sensibilities are the same here as in his later, famous documentary films. Plus, the soundtrack is both recorded sound and Duke Ellington (who, famously, loved and wrote tunes about trains).
Read more, and see the short here, on the Aeon site:
https://aeon.co/videos/d-a-pennebaker-transformed-documentary-filmmaking-this-is-his-first-film