In music, there are two common meanings for tuning:Tuning practice, the act of tuning an instrument or voice.
Tuning systems, the various systems of pitches used to tune an instrument, and their theoretical bases.
Man turning tuning pegs to tune guitar
Tuning of Sébastien Érard harp using Korg OT-120 Wide 8 Octave Orchestral Digital Tuner
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. 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 once the high overtones fade out. A tuning fork's pitch depends on the length and mass of the two prongs. They are traditional sources of standard pitch for tuning musical instruments.
Tuning fork by John Walker stamped with note (E) and frequency in hertz (659)
Quartz crystal resonator from a modern quartz watch, formed in the shape of a tuning fork. It vibrates at 32,768 Hz, in the ultrasonic range.
A Bulova Accutron watch from the 1960s, which uses a steel tuning fork (visible in center) vibrating at 360 Hz.
1 kHz tuning fork vacuum tube oscillator used by the U.S. National Bureau of Standards (now NIST) in 1927 as a frequency standard.