What is a tuning (pitch) fork?
A tuning fork is a simple metal two-pronged fork with the tines formed from a U-shaped bar of elastic material (usually steel). A tuning fork resonates at a specific constant pitch when set vibrating by striking it against a surface or with an object, and after waiting a moment to allow some high overtones to die out. The pitch that a particular tuning fork generates depends on the length of the two prongs, with two nodes near the bend of the U. Tuning forks can be tuned by removing material off the tines (filing the ends of the tines to raise it or filing inside the base of the tines to lower it) or by sliding weights attached to the prongs. Most tuning forks are tuned to concert pitch (A=440 Hz). When struck, then placed against an amplifying agent, such as a soundboard, the pitch can be used to tune a guitar.
