I have several favorite movies and TV shows with mechanical music:

Debbie Reynolds played the role of a lifetime in "The Unsinkable Molly
Brown."  She started out in a saloon learning piano by hand.  There was
a large upright disc music box in the brothel (probably a Regina).

The TV show "Bewitched" has an episode where she sets a Duo-Art grand
to start playing.

The HBO series uses an upright player piano several times -- in the
intro playing the theme song and often in their bar.

Doris Day's "By the Light of the Silvery Moon", and "On Moonlight Bay"
feature a Duo-Art grand in her father's living room.

Laurel and Hardy carry an upright player piano up a huge flight of
stairs with many mishaps then proceed to destroy it and the house in
"The Music Box".

The early TV series "Sherlock Holmes" has an episode where there are
three identical music boxes that each have an error in their music which
provides the location of the stolen loot.

Fred Astaire teaches Judy Garland to dance to a player piano in "Easter
Parade".  They start by pumping the piano but it continues playing
magically when they get up and dance.

These are the ones I thought of, and I'm sure there are many more.

Eli Shahar
Largo, Florida