Guitar Frets are laid out to accomplish an equal tempered division of the octave. Each set of twelve frets represents an octave. The twelfth fret divides the scale length exactly into two halves, and the 24th fret position divides one of those halves in half again. The ratio of the spacing of two consecutive frets is formula_1 (twelfth root of two). In practice, luthiers determine fret positions using the constant 17.817—an approximation to 1/(1-1/formula_1). If the nth fret is a distance x from the bridge, then the distance from the (n+1)th fret to the bridge is x-(x/17.817). Frets are available in
Fingerboard McLaughlin played with Shakti, along with Indian violinist L. Shankar, using an acoustic guitar with a fully scalloped fretboard. McLaughlin explained that this feature increased the ease and range of string bends by eliminating friction between finger and fretboard. The scalloped fretboard also facilitates the rapid, microtonal variation that is important in Indian music, as exemplified by classical Indian Sitar music. Without scallops, the guitarist must play microtones by sliding the string sideways on the fret. Experimental luthier Yuri Landman made an electric guitar for John Schmersal of Enon called the Twister with a partial scalloped neck for only the