A440 and the tuning exam (was A440=Fork)

[Jim Coleman, Sr.]

HI Terry:

Again, I have two or three things to suggest. In your first paragraph 
below you said 1 cent off would give you a 90% score. Wrong. You would
get 100%. It is only after the tolerance of 1 cent that the score goes
down for each .1 cent additional error. That's the good news.

Now for the bad news. As I wrote recently in this thread, when a certain
individual tried to outguess the effect of temperature change on his fork,
it caused him to fail the pitch exam. You need to know that the pitch is
right at the  exam piano. The only way I know is to have fork previously
tuned at face temperature and keep it that way. I'm not suggesting that
you keep the fork under your armpit during the entire tuning however. The
pitch cannot change much in the few seconds it takes to remove it from the
armpit to do the brief comparison with the F2. You could also, once the
A49 is in the ball park, tune a 5th down from A49 to use as a slow beating
reference while holding the fork in either hand as you make the fine
manipulations of the tuning pin. This would keep your fork stabilized and
ready for immediate checks. After you are satisfied that the A49 key has
been socked heavily and the pitch doesn't change, you can put the fork
under your belt or some convenient place against the body. Whenever you
want to refer to the fork again, just place it against your face to be
assured that its temperature is still in the ballpark, then do your test.

During this current series on forks, I haven't mentioned that you can also
use slow beating intervals for checks with the fork. D3 is a very helpful
note to use with the fork (just be sure that the D3 is on the wide side 
to start with).

Jim Coleman, Sr.

On Thu, 28 Oct 1999, Terry Beckingham wrote:

> This recent thread on the accuracy of tuning forks has made me wonder about
> the scoring of the tuning exam. Suppose, even though the examinee has a
> perfectly tuned fork, he or she is off by 1 cent on the pitch. This will
> result in a mark of 90 percent (although not a perfect score, still a
> reasonable mark). It is my understanding that the pitch correction number
> (PCN) has been eliminated. 
> 
> Now the examinee sets the pitch of A3 exactly to A4. He or she has then
> transferred this 1 cent error to A3. The examinee now tunes a perfect
> temperment from A3. This will result in a 1 cent error in every note of the
> temperment. A 1 cent error in the temperment area results in a 2.5 point
> deduction on each note. Therefore the examinee would end up with a score in
> the temperment area of only 67.5 percent and thus has failed the test
> without going any further.
> 
> Am I correct, or have I missed something here? 
> 
> I have two heavy nickel plated forks. One, which I dropped on a concrete
> floor 8-(, is 1.79 cents flat as measured by RCT, and the new one which
> replaced it and has never been dropped reads .81 cents flat. 
> 
> It has been suggested that the best way to tune a fork might be to establish
> the temperature by placing it under ones armpit and tuning it so that it is
> at 440 hz at that temperature. I believe that by the time the A4 has been
> set, the temperature would have dropped considerably from the 98.6 degree
> body temperature to a temperature much closer to that of the piano. This
> would leave the pitch sharp and introduce an error.
> 
> What a quandry. At what temperature should I tune my fork? So many
> questions, so many suggestions, so few concrete answers. It makes me wonder
> if I'll ever pass the test. I hope to attend a workshop with Virgil Smith in
> November. Perhaps he will have some suggestions.
> 
> Cheers all
> 
> Terry Beckingham
> 
> 
> 
> 
>