At about time 25:48 in the film, "The Amazing Adventure", a fellow
activates a player piano with coins.  The spoolbox detail raises
questions in my mind: what I see doesn't resemble a piano roll drawn
over a tracker bar.

I hoped for another glimpse of the machine, but no luck, so please
clew us in if you can tell us what that is!

https://www.youtube.com/watch?v=MesOQvRGkvE
 

Lee Rothrock

 [ The instrument might be a European café piano (Welte? Hupfeld?),
 [ playing a 5-tune roll.  -- Robbie