German term for keys on a piano or organ keyboard, or metal keys in an organ key frame.

1. Term denoting a system of tuning in which the various intervals are tempered or adjusted. The errors inherent in the chromatic scale of twelve half-steps are distributed among the intervals in such a way that each interval has a small error but none sounds offensive. 2. Loosely, that group of 13 or more notes in a piano, organ, or tuned percussion instrument which is first tempered during the tuning procedure. From this group of notes all other notes are tuned, directly or indirectly.

Tuned gourd-like hollow blocks, usually with a horizontal slit at the end, used as percussion effects in certain dance organs. Usually seen in sets of three or four. * Dutch: koppen.

Manually-set device which regulates the speed of a music cylinder, disc, barrel, or paper roll. Sometimes connected to a governor (also listed in this Glossary). In the Duo-Art Concertola roll changer, the tempo of each roll is punched into the leader according to a simple code, and the Concertola mechanism automatically sets the speed. * Synonym: speed control.

Small drum, usually under 12" diameter, without snares. (Compare to bass drum.)