Description
A tuning fork, or diapason, is a two-pronged metal fork that, when vibrated, produces a tone at a precisely known pitch. A tuning fork is constructed so that the tone produced is virtually unaffected by temperature and humidity. A good tuning fork produces very few overtones, so the sound approximates a pure sine wave. Some tuning forks have a sliding metal clamp so that notes other than the standard frequency, which is usually 440 or 880 hertz, can be played. The invention of the tuning fork is attributed to John Shore in 1711. John Shore was Sergeant Trumpeter at the English Court. Both Purcell and Handel wrote trumpet parts specifically for him. A tuning fork is used to tune a musical instrument. The note of the musical instrument corresponding to the pitch is adjusted—tuned—so that it matches the note of the tuning fork. Singers sometimes use a tuning fork to strike the correct note. Most tuning forks are tuned to the chamber tone, a', with a frequency (currently) of 440 Hz. There are also tuning forks for other pitches, including those other than a'. To properly hear the soft tone of a tuning fork, the fork is held with the rounded end against the head (bone conduction), mounted on a resonator, or pressed against a tabletop.
