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
Inlay (guitar) shape for their fret markers to create a brand identity set themselves apart from competitors. Gibson uses isosceles trapezoids while Fender uses dots, but others include lightning bolts, letters and numbers. Smaller dots are also usually inlaid into the upper edge of the fretboard or the neck so as to be more visible to the player who views the instrument from the side. LEDs or optical fiber can be employed to illuminate the markers. This is mostly employed by players who perform in front of live audiences where the lighting is either insufficient or constantly changing. On guitars, there are