Guitar harmonics

A guitar harmonic is a musical note played by preventing or amplifying vibration of certain overtones of a guitar string.

Music using harmonics can contain very high pitch notes difficult or impossible to reach by fretting. Guitar harmonics also produce a different sound quality than fretted notes, and are one of many techniques used to create musical variety.

Technique

Harmonics are primarily generated manually, using a variety of techniques such as the pinch harmonic. Another method utilizes sound wave feedback from a guitar amplifier at high volume, which allows for indefinite vibration of certain string harmonics. Magnetic string drivers, such as the EBow, also use string harmonics to create sounds that are generally not playable via traditional picking or fretting techniques.

Harmonics are most often played by lightly placing a finger on a string at a nodal point of one of the overtones at the moment when the string is driven. The finger immediately damps all overtones that do not have a node near the location touched. The lowest-pitch overtone dominates the resulting sound.