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
Romantic guitar Gagliano in Naples. This guitar, which was displayed in the Heyer Museum, Cologne before that museum was dispersed, showed some important differences from the modern classical guitar. It had 5 single strings, inlaid brass frets, a long neck relative to string length (the fretboard meeting the body at the 11th fret), a pegged bridge and a characteristic figure-8 shaped tuning head. It lacked only a sixth string to make it identical with the early romantic guitar. The earliest extant six-string guitar was built in 1779 by Gaetano Vinaccia (1759 – after 1831) in Naples, Italy. The Vinaccia family of luthiers