Tuning forks

[Susan Kline]

At 04:16 PM 10/28/1999 -0400, Jim B wrote:

>In a message dated 10/28/1999 3:04:59 PM, I wrote:
>
><<"Jim, can you enlarge on this? With the test, we're talking about precision
>to roughly <grin> 1 cent, more or less.">>
>
>Well yeah I can............A tuning fork is very sensitive to heat changes
>holding a relatively cold fork in your fingers will cause the fork to change
>pich very rapidly.  For instance I just tried this for this post
>:-)....................
>  I took my c523.5 cps fork that has been sitting out in room temperature for
>months now and checked it with my SAT, it was right on..........next I put it
>in the shop refrigerator right below the freezer compartment and left it
>there for 45 seconds..........checked it again (holding it very carefully as
>far away from the tines as possible) and it was two/three lights sharp on the
>SAT...................next I placed it in my hand for a ten count covering
>the tines and then checked it on the SAT and it was five or six lights
>flat................Now I don't know how to change lights flat and sharp into
>portions of cents ( Dr. Coleman???) but this shows there is a significant
>difference when measured.  Does this relate to a difference when setting a
>note??? you darned betcha......but is it gonna be a significant difference???

If you supply the audience with their own private ETD's, you could be in 
big trouble!

Actually, I just assure that the fork is pretty mild as far as temperature 
goes.
If it is hot from being in the car, I lay it on the plate while I put in 
the strip. If it is cold, I hold it in my hand till it seems to be more or 
less at room temperature.

><<"If there's any reason why a piano tuned for a concert needs to be any
>closer than that, I would be interested to find out what it is! ">>
>
>  Well you have allowed your  camel to stick his  nose under a tent where it
>shouldn't be :-)

Fatima! You get your nose out of there THIS INSTANT!

>At least this isn't what I was referring to........was pitch as requested,
>i.e., A440? A441? A442? A435?, what temperament (some are less pitch
>dependent/reliant than others), were the venue lights turned on before
>tuning? Is there heat/air conditioning in the venue? these and more,
>including the things you mentioned, go into determing pitch and where it
>would be set initially. Was your fork hot or cold? Just how do you set 435?,
>or 441?, or 442? when all you have is an A 440 fork? Does inharmonicity play
>a role in offset tuning? F to A440?, If so how much? And does the same apply
>to the other pitches?

I see I've been getting a free ride. The Arts Center keeps the temperature 
constant, not that hard to do in the mild climate; (the heating/cooling 
system runs around the clock.) The lights on the little stage aren't all 
that hot. No one has ever requested anything but ET. In fact, they don't 
request ET, either, they just take it for granted. (Life in the provinces 
...) The orchestras (all two little ones) seem willing and able to tune to 
A440 and match it pretty well, and hold pitch pretty well, since the 
temperatures stay pretty steady. Yes, a lot of "pretty", but life is full 
of approximation, n'est ce pas? The piano pitch seems to be the least 
variable variable, so to speak.  ["variables don't; constants aren't"]

>   In other words I suppose a piano tuned in a dark venue with no heat or air
>is not going to be where you put it when the Ochestra is rehearsing and the
>lights and heat/air have been turned on so it don matter much noways how hot
>or cold yo fork is :-) And what happens to the woodwinds as they go sharper
>and sharper (?) during the concert? or the strings as they go flatter (?)

Fatima leaves her droppings right outside the stage door, since she's very 
sensitive to bad intonation ... but no one else manages to notice much, I 
think. Luckily the musicians here are better than the conditions are bad. 
That is, the changes they are called on to make are within their capacity 
to accommodate.

>   The thing to do with a fork (my opinion) is to calibrate it a known
>temperature such as has been alluded to, i.e., armpit, under the belt, in
>your back pocket, etc.  Or you can let it float to the temperature of the
>plate, which is what I prefer, not having arm pits large enough to hold a
>grand under :-),  from that point you will know whether the pitch needs to be
>sharp or flat of your fork, nes pa??  Besides if you sets de pitch within a
>hemi, semi demiquaver y'all gonna be a hero no how .....!!

Y'all gwine be a hero if y'all's unisons hold like they wuz carved in 
stone; if y'all's octaves (all uv um) are pleasantly tasteful; if y'all don 
drag yo tail in late ... if yo pedal don make a scrawwwwww racket; if yo 
dampers don hang in de air ... etc.

It seems to me that we are talking about two things: the change in pitch 
from the fork temperature, and the change in pitch as the piano warms and 
cools. The piano changes much more slowly, and is much less under our 
control. I suppose that one could heat or cool the fork to a temperature 
chosen to accommodate the expected change in the piano; but why not change 
the beat rate of A against F instead? And I see no point in having the fork 
the same temperature as the plate, since the piano and fork will change at 
a different rate anyway, as they heat or cool. It seems more important to 
have the fork at roughly the same temperature you always have it, and to 
know what the pitch of it is at that temperature.



>   To the person who asked the original question about fork temperature...do
>the best you can, with whatever procedure you feel the most comfortable with
>and you will not go wrong and you will be within the 1 cent margin.
>My view.
>Jim Bryant (FL)

I concur. If you can match pitch as close as the accuracy of a decently 
tuned fork, you'll be doing just fine.

Susan


"If all else fails, read the manual."