A barrel organ.
barrel organ definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a mechanical musical instrument having a cylinder studded with pins which open pipe valves or strike metal tongues when the cylinder is revolved, producing a tune; hand organ
barrel organ definition by American Heritage Dictionary
A mechanical instrument on which a tune is played by the action of a revolving cylinder fitted with pegs or pins that open pipe valves supplied by a bellows.