Buzz Feiten system

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Paul E. says:
>Yes. As much as I agree with Neil that it would be more valuable to
>start educating guitarists on microtonality than obsessing over getting
>perfect 12tET, it is the latter that Feiten's system is geared toward.
>In addition to the usual bridge adjustments, Feiten proposes some
>string-specific nut adjustments. I remember Steve Vai saying he is
>getting Feiten's system installed on all his guitars, as he was never
>before able to play chords anywhere on the fingerboard and have them all
>sound in tune. When playing along with keyboards, etc, it is 12tET that
>defines whether one is in tune or out of tune, and deficiencies in 12tET
>itself are not really an issue to most musicians, who have never spent
>time listening to purer intervals.

I will admit to not knowing the details of the BF system, but here are
some basics to consider when deciding if the method does what it is
supposed to do. Assuming that the guitar is properly set up:

1. Adjusting the nut height can only affect the amount a string stretches
when it is fretted. A correctly cut nut should leave the same distance
from the string to the first fret as there is from the string to the
second fret when the string is fretted at the first. Normal compensation
at the bridge corrects for the different amount strings of different
guages stretch. Traditionally, bridge compensation is checked at the
octave, where the bow of the neck, and thus the stretch of the strings
will be the greatest. It may be that compensation should be adjusted
relative to lower frets, where most playing is traditionally done.

2. Adjustment of the position of the fulcrum of the nut along the length
of the string might assist in retuning out of tune thirds in common barre
chords. This is "the same" principle that Steinberger uses in their
TransTrem whammy bar (by the way, I have always thought that a
Steinberger guitar with a transtrem would make a great microtonal
instrument, since you can adjust the pitch of each string separately when
modulating to one of five new key centers).

3. No matter how you compensate for string guage and other variations on
a guitar, you are still left with 12TET frets, and, for example, a
compensation that
corrects the third of an Emaj barre chord (one that flats the G string)
will incorrectly compensate the octave of a A barre chord in the same
region, and a correction of the third of the A barre on the B string will
ruin the "perfect fifth" of the E barre.


John Starrett
http://www-math.cudenver.edu/~jstarret