In the July, 2002, issue of Piano Technician's Journal, published by
the Piano Technician 's Guild, is an article by the inventor of the
self tuning system.  Please see http;//www.ptg.org/ to order reprints,
if interested.

To stimulate interest, the concept is that when a piano string gets
warm it goes flat, when it looses heat it goes sharp.  Warming the
strings is accomplished by passing a current through them.  Computer
technology determines what frequency the string is at, and then
determines how much electricity to deliver to the string to get it
to the predetermined frequency.

The predetermined frequency is found for each instrument by an
aural tuning, which is then recorded for that piano in a memory chip.
A prototype impressed Dick Dolan, president and CEO of QRS Music
technologies: "He was flabbergasted and an agreement was struck
shortly afterward."

A number of problems to solve in a "self tuning" piano are neatly
overcome.   For example, how are the strings sounded?  Not from the
player unit as one might suspect, but by a "magnetic oscillating field
physically driving the string....".   Well, I suppose the damper pedal
must be pushed down (damper lift mechanism activated) so a player unit
does come into play.

The inventor claims pitch measurement to "1/200 (.005) of a cent".
This is by far closer than the ear can detect.  As an example a .005
cent difference at 440 cycles per second would be 440.0013, or .0013
beats in one second, so how many seconds to hear one beat?  This can't
be right, 769 seconds?

This gets cut in half by each octave going up but doubles each
octave going down.  1/100 of a cent is claimed by the top of the line
electronic tuning devices (ETDs), but really, 1/10 of a cent is about
as good as you can get since the string does vary in frequency
throughout its vibration period.  (Very little, probably, on a scale
measured only by relativity has to do with elasticity.  After all,
a vibrating string must be warmer than a non vibrating one.)

 [ Right, and improbable!  The accuracy is the inverse of the period
 [ of observation: you must listen for at least one second to detect
 [ a beat frequency of 1 Hz, and so on.  So, although the pianos
 [ computer might have 1/200 cent resolution, in practice it won't
 [ listen long enough to attain the implied precision.  -- Robbie

Anyhow, a lot of claims are made for this innovation.  The concept
is interesting, but as a piano tuner I am skeptical for a number of
technical issues related to tuning a piano that may or may not have
been considered.

There is supposed to be a working model at the NAMM [National
Association of Music Merchants] convention coming up January 15th,
2003, in Anaheim CA.  I am planning to attend so can I post a report
if there is interest.  If anyone wants to know of a particular booth
or company there please email me at <remoody@midstatesd.net> and
I will try to check it out.

Richard Moody,
Piano Tuner (associate member, PTG)

 [ Ask what Story & Clark is doing to allay the doubts of piano
 [ tuners and techs.  I'm sure they realize that they need the
 [ support of these folks.  -- Robbie