JND (Foote)

[A440A@aol.com]

Greetings all, 
Bill writes:
<< Especially in light of the undeniable fact that few of
those who insist that ET is the "normal" or even "common law"  (Ha! Ha!, what
a joke!) temperament ever even really get it truly "equal".>>

      Bill, you have used this statement  repeatedly used to bolster the
argument that HT's are interchangeable with what the majority of technicians
are providing, and I think it does a disservice to me, them, and yourself.   
   There is a standard unit of measurment called JND.  This is for 'just
noticible difference".  Differences less than this can be disregarded without
alteration of the validity of the equation.  
   The divergence from perfectly, mathmatically, exact ET can be ignored in
considering whether a temperament is valid ET or not, if the divergence falls
below the JND.  What is noticible in one place is not in another, so the JND
is not a set quality.  I offer two examples:
    A mild Victorian tuning on Ronnie Milsap's piano had him calling his other
tuner the next day to come tune the piano in ET.  I heard about it and called
Ronnie  to ask what it was that bothered him.  He said  that when he wanted
"all of the chords to sound alike".  His JND here was about 3 cents in the
worst third. 
    I tuned a Balwin grand, eight years after it was purchased new.  It was
the first tuning for the piano, and when I finished a 120 cent pitch raise,
the customer asked if I had tuned all the notes, saying she really didn't hear
the differernce.  This is a different JND.

     The "ET" that is tuned today to the standard of the Guild test is well
within the JND of the vast majority of consumers, and to call it "non-equal"
for lack of perfection is, in my opinion, missing the point at best, and
misleading to the non-technician.  It is just not a legitimate claim. 
Regards, 
Ed Foote 
Precision Piano Works
Nashville, Tn.