Volume Control Key

Most jukeboxes used Volume Keys as a way to stop people from monkeying with the sound when the jukebox was on location. They would give the key to the staff so they then could set it as needed...

These keys started with the earliest jukeboxes - if your volume control has a small plate with two holes in it then this key is for you - or if the volume control has a simple slot or a slot with a center bit to stop screwdrivers.