Guitar harmonic

A string harmonic is a string instrument technique which uses the nodes of natural harmonics of a musical string to produce high pitched tones of varying timbre and loudness. String harmonics are, "high pitched tones, like a whistle's, are produced when the musician lightly touches certain points on a string." "A flute-like sound produced on a string instrument by lightly touching the string with the finger instead of pressing it down," against the fingerboard (without stopping).

A harmonic may be measured by the location of the node pressed. The primary pitch perceived in a harmonic may be estimated using the complement of the inverse (pressing nodes dampens certain harmonics and brings out others, so every harmonic has multiple simultaneous frequencies, but the x/y harmonic is usually heard as the pitch y/(x-y)). Thus when the harmonic played with the node in the middle of the string (1/2), is played, the note heard is the octave (2/1 = 2/(2-1)), the node at 1/3 produces a perfect fifth (3/2 = 3/(3-1)), and the node at 2/3 produces a compound perfect fifth (3/1 = 3/(3-2)).

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