That is not what ‘drone’ means in a musical instrument context. Unless the function of these drones is to emit a constant underlying tone to add to the musical

That is not what ‘drone’ means in a musical instrument context. Unless the function of these drones is to emit a constant underlying tone to add to the musicality, allowing you to mimic bagpipes, a banjo or a tambura. Which has clearly always been the ambition of any serious pianist.