Small piece of wood, hinged at one end and faced with soft leather, used to cover an opening in a pipe chest, reservoir, or other pneumatic apparatus. Turns the flow of air (to an organ pipe, pneumatic, or other device) on and off when actuated.

See safety check.

German term for tympani.

A metal finger with a pointed end that engages with a ratchet gear and holds the power in check. Sometimes called a "click".

1. A foot-actuated lever. (The term foot pedal is redundant; pedal is sufficient.) See soft pedal, sustaining2. The division of a pipe organ containing large bass pipe ranks (together with auxiliary smaller ranks) and controlled by the pedal board (a series of levers in the shape of a large keyboard played by the feet).