Klarinet Archive - Posting 000027.txt from 1999/01

From: Tony@-----.uk (Tony Pay)
Subj: Re: [kl] re:Intonation training
Date: Sat, 2 Jan 1999 07:54:49 -0500

On Sat, 02 Jan 1999 04:08:58 -0800, studiorenaud@-----.com said:

> Edwin V. Lacy wrote:

> > I have questioned many of them about precisely this question, and
> > their answer has always been That the partials *must* be whole
> > number multiples of the frequency of the fundamental."
>
> This is probably negligible for wind instruments, where we are
> vibrating a very free column of air, never less there is always some
> inertia, even in air, and clarinets.

The distinction between wind instruments and pianos is that the wind
instrument is a 'driven' oscillation, whereas the piano isn't. It is
this that forces the partials to be whole number multiples of the
fundamental.

For a wind instrument there is also the phenomenon that above a certain
frequency, called the 'cutoff freqency', the length of the tube has no
effect: sounds above that frequency don't get reflected at the 'open
air' (ie the first open fingerhole or thereabouts), so it's as though
above that frequency you just have reed 'noise' (vibration uncontrolled
by the tube) that gets squirted through.

I've always understood that this is why intonation between two or more
instruments playing high can be such a tricky number. Even if the
partials were harmonic, there could be a problem with 'beat'
frequencies, which are high enough to be heard and might not fit with
the harmony. But the added complication of inharmonicity could make it
even worse.

This would explain why choosing a different fingering sometimes helps --
for example, the loud concert C# between fl, ob and cl in Pictures at an
Exhibition works better if you use a fingering that is a harmonic of a
shorter tube (throat A flat plus speaker plus ?, say).

But I'm sure some acoustician knows more about this....

Tony
--
_________ Tony Pay
|ony:-) 79 Southmoor Rd Tony@-----.uk
| |ay Oxford OX2 6RE GMN family artist: www.gmn.com
tel/fax 01865 553339

"Believing Truth is staring at the sun
Which but destroys the power that could perceive."

-------------------------------------------------------------------------
Unsubscribe from Klarinet, e-mail: klarinet-unsubscribe@-----.org
Subscribe to the Digest: klarinet-digest-subscribe@-----.org
Additional commands: klarinet-help@-----.org
Other problems: klarinet-owner@-----.org