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
Ten-string guitar Nazareth, and George Kooymans of Golden Earring. Close relatives of the guitar with ten strings include: Ten-string guitar There are many varieties of ten-string guitar, including: Harp guitars are guitars to which extra strings have been added which are never fretted but may be plucked or strummed. These strings are therefore played in a manner similar to those of the harp, while those of the principal neck are played as a guitar, hence the name. Often a second neck, parallel to the fretboard, carries these extra strings. There have been many designs of harp guitar, but in the nineteenth century