tuning fork

In music, a device for providing a reference pitch, invented in England in 1711. It is made from hardened metal and consists of parallel bars about 10 cm/3–4 in long joined at one end and terminating in a blunt point. When the fork is struck and the point placed on a wooden surface, a pure tone is heard.

There are tuning forks for each musical pitch. A is known as ‘concert pitch’, since the instruments of the orchestra are tuned to A above middle C.