Many years ago, about 1950, I saw a black-and-white movie which
showed a reproducing piano playing, an upright I think it was.
In the movie there is a murder, a hand fires a gun, and the police
are unable to locate the bullet, which lodges in the piano roll.
Later a police officer is investigating the scene, the piano is
playing, and he hears a discordant sound from the piano due to
the bullet hole in the roll.

Well, he must have known something about pianos, because he stops
the roll, rewinds it and extracts the bullet!  What I would like to
know: does anyone know the name of the movie, and is it available?

Brian Lackie, Australia