String harmonic tap the fifteenth fret, as . Tap harmonic is a technique used with fretted string instruments (usually guitar). It is executed by tapping on the actual fret wire, most commonly at the 12th fret, but also can be executed by tapping any of the fret wires with proper technique. It can also be done by gently touching the string over the fret wire instead of tapping the fret wire if the string is already ringing. See also: Shred Guitar. This technique is used by effect devices producing a magnetic field that can agitate fundamentals and harmonics of steel strings. There
String vibration or, perhaps more easily, by adjusting the machine heads, to obtain the same, or a multiple, of the AC frequency to achieve the same effect. For example, in the case of a guitar, the 6th (lowest pitched) string pressed to the third fret gives a G at 97.999 Hz. A slight adjustment can alter it to 100 Hz, exactly one octave above the alternating current frequency in Europe and most countries in Africa and Asia, 50 Hz. In most countries of the Americas—where the AC frequency is 60 Hz—altering A# on the fifth string, first fret from 116.54 Hz to