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
Tenor guitar six string guitar. As string tension for any pitch increases with length, some have said these guitars cannot be tuned to the normal CGDA fifths tuning because the A string cannot be tuned to pitch without breaking. However, there are a variety of available methods for addressing this point and bringing the longer-scaled tenor guitar up to standard tuning and pitch: special string sets; strings extracted from a seven string guitar set; etc. Tenor guitars can also be tuned to a reentrant CGDA tuning where the A and sometimes the D are pitched an octave lower. The plectrum guitar is