PTG tuning test info?

[fssturm@unm.edu]

Quoting Isaac sur Noos <oleg-i@noos.fr>:

> Hello,
> 
> As a 2 cts diff at the lower end of the temperament is the same that
> a
> 1 cts error in the top, I wonder also how is it measured.

Cents are proportional to the half step throughout the piano. In fact, a smaller 
number of cents will produce a larger "beat" difference in the upper ranges, 
which is what you are saying. However, the test has been established with a 
single "margin of error" in each segment of two octaves or so. And it seems to 
work reasonably well: almost all errors are verified aurally (very few are thrown 
out because they are not verified by the examiners). A "beat-based" system 
would probably be more exact, but mathematically more troublesome. With 
modern computer-based devises, this is much less of a problem than when the 
test was devised, at which time the old "SOT" (Sight-O-Tuner) was the cutting 
edge, and needed to have a reduction knob added to get 1/10 cent resolution.
> 
> What I wonder also is how the EDT can prove the temperament to be
> right or wrong, the fundamental may be measured, I seem to recall
> that
> the second partial was the first measurable partial with SAT or RCT
> .
The partial measured in the test is the 1st, 2nd or 4th partial (depending where 
in the scale). For most of the piano it is not the same partial as is used on the 
SAT or RCT. It doesn't really matter that much which partial is read, as long as 
you can get reasonably good resolution with the EDT (ie, reproducible readings 
within a fine range). The examinee's tuning is read, and it is compared with a 
master tuning (that was created earlier by a committee on the same piano, and 
recorded). 
> 
> May be I am wrong on that one, I understand also that the jury is
> listening to the temperament so he can correct any obvious error of
> the EDT.
> 
The examiners verify a good portion of the errors identified in the comparison 
between master tuning and examinee's tuning - not just in the temperament 
area. At no point is an EDT generated tuning used as a standard. The master 
tuning is established aurally, by a committee of three RPT's (including one CTE 
- certified tuning examiner). It is read using an EDT, and the numbers are 
recorded. This master aural tuning is the standard against which the examinee's 
tuning is tested.

> What I don't get is that the temperament is better evaluated with
> unisons tuned , in my opinion, because then you have the definitive
> beat rates and not a partial view of the work.
> 
Yes, it would make sense to have the examinee tune a whole piano. Harder to 
administer the exam, though. The whole issue of a standardized exam is a 
troublesome one.

> Just some Euro...
> 
> Best Regards.
> 
> ------------------------------------
> Isaac OLEG
> accordeur - reparateur - concert
> oleg-i@noos.fr
> 19 rue Jules Ferry
> 94400 VITRY sur SEINE
> tel: 033 01 47 18 06 98
> fax: 33 01 47 18 06 90
> mobile: 033 06 60 42 58 77
> ------------------------------------
Regards,
Fred Sturm