# guitar fret decreasing down a guitar

by ramly
Tags: decrease
 P: 9 why does the spacing decrease going down the neck of a guitar? using physics concepts how would this be explained? (equations and concepts)
 P: 349 To double the frequency of a note the string length must halve (assuming tension is constant) To produce any fractional change in frequency the length must change by the same fraction (or1/fraction) Every halving of the length results in a doubling of the frequency, the frets get closer.
 Engineering Sci Advisor Thanks P: 6,033 The frequencies of the Western musical scale of 12 semitones in a octave are a geometric progression, with a factor of ##2^{1/12}## between each frequency. The string lengths decrease in the same ratio. Incidentally, the value of ##2^{1/12}## is very close to 18/17, which was (and probably still us) the ratio used by traditional guitar makers, who positioned the frets by making a drawing with a straight-edge and compasses, not by calculating and measuring.
P: 1,331

## guitar fret decreasing down a guitar

 Quote by AlephZero . Incidentally, the value of ##2^{1/12}## is very close to 18/17, which was (and probably still us) the ratio used by traditional guitar makers, who positioned the frets by making a drawing with a straight-edge and compasses, not by calculating and measuring.
You might not be able to hear the difference betweeb 18/17 = 1.0588 and 2^(1/12) = 1.0594, but you'll definitely be able to hear the difference between (18/17)^12 = 1.9856 and 2, so the traditinal guitar makers can't have made all their intervals 18/17.
Engineering