Organ Cobs
Organ cobs or rollers were used in roller organs, and consisted of a cylinder of wood with pins in them that pressed on the keys in the organ to actuate them. Roller organs were a type of reed organ introduced in the late 1880s by the Autophone company of New York, and were an inexpensive and popular means of entertainment for the US market.

Museum of Obsolete Media, CC BY-SA 4.0.
Further reading