Refretting guitars

Ladies and Gentlemen-
Common practice in guitar building is to fret the neck as if no
string stretching would take place and compensate at the bridge for the
stretching that takes place when the guitar is fretted at the octave
(12th fret, 31st fret, whatever determines the octave for any particular
instrument). This is a compromise between accurate tuning over the
whole neck and ease of setting the bridge piece (comparing the pitch of
the open string or octave harmonic to that of the string fretted at
the octave can be done by ear). I know of no realistic way to build a guitar
that has
correct stretching compensation over the whole neck, but if you lay the
frets out with no compensation for stretching and adjust the bridge to
give correct pitch in the area you expect to play in most (rather that
at the octave), you will probably be quite satisfied with the results.
There are a few builders working on computerized retunable guitars,
so that the artist can quickly change string tension, but these are not
currently operating well enough for discriminating users. Certainly a
guitar could be built in which the position of the bridge pieces were
quickly adjustable to account for stretching at different locations on
the neck (servo or stepper motor control or some mechanical linkage), but
this seems like overkill for a relatively small problem. When a guitar is
well set up (proper neck relief, nut height, bridge height, string guages,
etc), the standard octave compensation is surprisingly good.
Also, please do not consider movable nut pieces to compensate for
string stretch. The nut should have the same function as a zero fret, and
if it is accurately placed and set it will act as a zero fret.
In short, put the frets where they should be assuming no string
stretch from fretting, set the guitar up properly and then adjust the
bridge to compensate in the middle of the most played area.
John Starrett

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Thanks alot to Pauls H and E for commatic commentaries! Will pick
up thread tomorrow. (No more lunch-hour left).

Patrick