Klarinet Archive - Posting 000436.txt from 1998/09

From: "Dan Leeson: LEESON@-----.edu>
Subj: Re: [kl] Re: Pitch standards
Date: Mon, 14 Sep 1998 15:35:05 -0400

> From: MX%"klarinet@-----.98
> Subj: Re: [kl] Re: Pitch standards

> >> Dan,
> >> I'm at a loss here. If in fact a pitch standard is set at a'=440,
> where
> >> does temperature come into effect? It is a vibrational standard only.
> >> The currently adopted _standard_ of a'=440 (in 1939) is irrespective
> of
> >> temperature; while the setting of an orchestra's tuning pitch may be
> >> other than a'=440 for physical reasons (including that of
> temperature),
> >> we can only say that they are tuning to something other than the
> >> standard; say, 2 Hz above or 2 Hz below the _standard_. If otherwise
> (if
> >> the _standard_ is allowed to vary) then there would be no such thing
> as
> >> a standard at all.
> >>
> >> You can have a pitch standard of 442 Hz, but to call it a' would be
> >> incorrect. It could only be called a vibrational standard of 442 Hz
> or a
> >> standard vibrating 2 Hz faster than the official standard of a'=440
> Hz.
> >> An orchestra may call it A, may finger it as A, may huff and puff and
> >> whatever - but it isn't the official a'; at least, not until a
> >> contentious bunch of grumpy people decide to call a'@-----. _Then_
> >> A'@-----.
> >
> >I think it to be a matter of physics. If something is vibrating
> >as a certain speed, that same material will vibrate at a different
> >speed if the temperature is changed. Thus the pitch will change.
> >
> >Also, I believe that the standard for pitch states a material
> >of a certain nature (such as a tuning fork made of platinum or
> >gold or whatever) vibrating at a certain frequency produces a
> >specific pitch at a given temperature. Change the material,
> >the frequency, or the temperature, and you affect the pitch.
> >
> >If I remember correctly, the first attempt at having a standard
> >pitch was called "Stuttgart pitch" and it specified a vibration
> >of 430 at a temperature of 18.6 degrees centigrated. I once
> >had to look it up in Groves (which I do not have a copy of
> >at home) and was surprised to see the temperature so carefully
> >described.
> >
> >Any orchestra would complain about their ability to achieve
> >a predefined pitch if the room were too cold or too hot. My
> >orchestra even had it in the contract; i.e., if the temperature
> >was too hot (for outdoor concerts, obviously) we did not have
> >to play, it being considered dangerous for the instruments and
> >the inability to achieve a specific pitch standard.
>
>
> Dan,
> The reference standards themselves (the physical embodiments) are
> temperature correlated; i.e., they are only standards given particular
> physical environments. If the environment does not meet some certain
> specifications, then the "standard" does not apply. In other words, if I
> have a tuning fork made which represents the standard of a'=440 at 72
> degrees F., and I take it to a place that is 85 degrees F/, then it is
> _no longer_ a standard. It is a tuning fork which beats at an incorrect
> frequency, not the frequency of the standard it was constructed to
> match.

I think what you are saying is that temperature is implicitly
contained within the statement of the standard, and I can live
with that so long as it is realizied that, explicit or implicit,
it is part and parcel of the entire technology.

>
> The scalar value of a'@-----. The
> physical embodiment of the standard may. You remember crystal ovens,
> right? A quartz crystal, cut or grown in a particular orientation,
> vibrates at a particular frequency when excited by electrons. To use
> these crystals _as standards_, their temperature had to be controlled
> very precisely (along with using an orientation that did not show much
> temperature deviation). In another usage, the frequency difference
> between a temperature stabilized crystal and one located where one
> wished to measure a temperature was used to determine the temperature.
>
> Of course, that leads us to the slippery slope of temperature and time
> standards ...
>
>
> -------------------------------------------------------------------------
>
=======================================
Dan Leeson, Los Altos, California
Rosanne Leeson, Los Altos, California
leeson@-----.edu
=======================================

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