As to the origins of people thinking there were player pianos in old
Western movies, my guess is it comes from the sound track.  Ragtime
and other popular tunes of the day, played by a sleeve-gartered piano
maestro on a rinky-tink out-of-tune upright piano in the parlor of
a gambling saloon or sporting house, is a common image and may have
started the misapprehension.  Another good reason to keep our
instruments in top condition!

Jim Katz