What was invented in 1711 by British musician John Shore?

John Shore (c. 1662 – 1752) was an English trumpeter. He invented the tuning fork in 1711. Shore was Sergeant Trumpeter to the court, who had parts specifically written for him by both George Frideric Handel and Henry Purcell.

A tuning fork is an acoustic resonator in the form of a two-pronged fork with the prongs (tines) formed from a U-shaped bar of elastic metal (usually steel). It resonates at a specific constant pitch when set vibrating by striking it against a surface or with an object, and emits a pure musical tone after waiting a moment to allow some high overtones to die out. The pitch that a particular tuning fork generates depends on the length and mass of the two prongs. It is frequently used as a standard of pitch to tune musical instruments.