1. Finger-operated control lever used to sound a note on a keyboard instrument such as a piano, organ, or accordion. 2. Musical pitch of an instrument or music arrangement (e.g., the key of C). 3. Actuating levers, usually made of brass, used to operate organ reeds (as in a cylinder music box with reed organ attachment), organ pipes (such as in a large barrel orchestrion), or a pneumatic system (as in the key frame of a fairground organ). 4. Key(s): the number of playing notes plus the number of control stops (for changing registers, stopping the instrument at the end of a song, rewinding the roll, etc.) on an automatic musical instrument, especially a dance organ or fairground organ (such as 89-key Gavioli organ, 101-key Mortier organ, etc.). * French: touche * German: Tasten, Tonstufen.