Equally memorable is the scene, I think it’s in Laurel and Hardy’s Saps at Sea, where Stan pulls his mattress off of his cot, and plays the wire strings underneath as a harp in a magnificent solo.
The movie about Catherine the Great starring Marlene Dietrich has an arrangement of Rubinstein’s music that features marvelous sounding harp parts.
Saul, you are thinking about the Laurel and Hardy movie “The Flying Deuces.” There is a clip on youtube. Go to youtube, type “Laurel Hardy bed harp.” Maybe someone can post the link.