What is the X in X-mas?
(from Old French flageol: "pipe," or "tabor pipe"), wind instrument closely related to the recorder. Like the recorder it is a fipple, or whistle, flute-i.e., one sounded by a stream of breath directed through a duct to strike the sharp edge of a hole cut in the side of the pipe. The name flageolet was applied to such flutes at least from the 13th century, but from the late 16th century it has referred most specifically to a form of the instrument developed at that time in Paris. Its principal, or French, form has a contracting bore with four front finger holes and two back thumbholes. From the mid-18th century the beaked mouthpiece formerly used was replaced by a narrow tube of bone or ivory that led to a chamber maintaining steady air pressure and holding a sponge to absorb breath moisture