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
Seven-string guitar Classical, Jazz, Rock, Progressive Rock, and Heavy Metal. The Seven-string works well in a band setting, as its lowest note, B1 lines up well with the B0 commonly used for the lowest note of a 5+ string bass. Both the guitar and bass could drop tune as well using a lowest note of A1 and A0 respectively (with the bass this extends the range to the lowest note on a standard piano). Seven-string guitar The seven-string guitar adds one additional string to the more common six-string guitar, commonly used to extend the bass range (usually a low B) or also