Introduction
EVERY Iuthier has certain ideas about fretting an instrument , and, while the result
ts neuer perfect (for perhaps obuious reasons), the compromise solutions are generally
satisfactory for most purposes.
Now Francisco Estrada Gómez, from Buenos Aires ín Argentina, has come up
with another method.
He has receiued praise from uarious fellow-Argentinian guitarists, among them Roberto Aussel,
Eduarda Falú, Irma Canstanzo. Horacto Ceballos, Maria Isabet Siewers, and Graciela
Pomponio de Zarate.
We offer the findings of his long research to our readers, or those of them who make guitars,
in the hope that they will find them of interest.
ACCORDING to tradition, a gultar is fretted by sing the geometric progression
worked out by the German physicist Frederiek Chlandi in 1809.
He placed the twelfth fret in the middle of the string where the second harmonic is produced.
The sound made by a free string should, then, have half the vibrations produced
by the second harmonic or pressed fret 12.
And it would indeed be so, were it not for the fact that the string lncreases
its tension when pressed against the fingerboard. In order to solve this problem,
Iuthiers have had, so far, to displace the support of the string on the bridge to a convenient
measure Thus, the subsequent divisions of the fingerboard are placed according to a
geometric progression whìch bears no connection to the new length of the string.
New geometric progression for fretting stringed musical instruments - (tempered scale)
1) Set the length of the string (diag.1 N22)
2) Place a fret so that by plucking a free string Ifirst harmonic) you can produce half
the vibratlons of the pressed strtng (second harmonic).
Obviously, to do so the fret must be placed approximately in the middle of the string.
I say 'approximately' because the pressure of the strlng being pressed against the fret
produces a slight increase in its tension (increase of frequency)
that must be compensated by making part a slightly shorter than part 'b' (see diag. 1).