Classical guitar fingerboard and placed at points that divide the length of string mathematically. The strings' vibrating length is determined when the strings are pressed down behind the frets. Each fret produces a different pitch and each pitch spaced a half-step apart on the 12 tone scale. The ratio of the widths of two consecutive frets is the twelfth root of two (formula_1), whose numeric value is about 1.059463. The twelfth fret divides the string in two exact halves and the 24th fret (if present) divides the string in half yet again. Every twelve frets represents one octave. This arrangement of frets
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