Klarinet Archive - Posting 000257.txt from 2004/12

From: "Dee Flint" <deeflint01@-----.net>
Subj: Re: [kl] Followup question: Greenline and temperature
Date: Wed, 15 Dec 2004 20:19:58 -0500


----- Original Message -----
From: "Vann Joe Turner" <medpen@-----.net>
To: <klarinet@-----.org>
Sent: Wednesday, December 15, 2004 6:20 PM
Subject: [kl] Followup question: Greenline and temperature

> Hi All,
>
> Thanks to all for the reponses to my question. I get the list in digest
> form, and so can't reply directly to a response.
>
> I'm puzzling over how the pitch is markedly influenced by the temperature
> of
> the air. I see the logic in it, but am troubled by the oboe. If it is true
> that the oboe's A is remarkably in tune, why isn't the oboe's pitch
> affected
> by the temperature of the air column? (Perhaps it is, and I just haven't
> heard -- for I've been away from my horns for 30 years while making a
> living!)
>
> Best wishes,
> Vann Joe Turner
>

Basically it's like this:

Speed of sound = Frequency x Wavelength

Thus:

Frequency = Speed of Sound divided by Wavelength

Now the speed of sound is a function of the air temperature and density. So
when the temperature or density changes, the speed of sound changes.

Wavelength is a fixed number based on the "open" length of tube (i.e. how
many holes are covered).

So since the speed of sound has changed and the wavelength cannot change
(for a given length), the frequency (i.e. the pitch) must change.

That's the nickel tour!

Dee

Thus

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