One of my favorite keyboard instruments is the pneumatic player piano. My grandparents had one in their basement when I was little, and they had a closet full of rolls. When I was very young, it worked, and my grandpa would operate it with its pedals. As I got older--or, more pertinently, as my grandparents got older--its playback mechanism fell into disrepair, but it still functioned as a regular piano.
One of the interesting things about the player piano is that the various manufacturers got together in the early 20th century and developed a standard format, so that one company's rolls could play on any other company's pianos. This is the best kind of history to repeat itself.
Anyway, I've always been fascinated by the instrument, and it certainly threw some gasoline on my later interest in synthesizers.