We know that all objects in the Universe have their natural frequencies. Some may be simple but some, complex. A renowned example for an object with a simple natural frequency is the tuning fork. It is an acoustic resonator that appears as a two-pronged fork with the prongs or tines formed from a U-shaped bar of elastic metal like steel. Depending on the length and mass of the two prongs, the fork produces a pitch. Generally, it is used as a standard of pitch to tune musical instruments.
As mentioned earlier, a tuning fork has a natural frequency. When set vibrating by striking against a surface, or by an object, the fork resonates at a specific pitch and emits a musical tone once the high overtones have died out.
Traditionally, the forks have been used to tune musical instruments. But today, electronic tuners are replacing them in applications.
The tuning fork was invented in 1711 by British musician John Shore, who was a trumpeter and lute player.