Author: Matt74
Date: 2020-11-09 08:39
I’ve wondered about the same thing.
Best guess:
First the overall frequency, then the reed itself.
Overall: The reed produces the vibration in the air column, but the column partially controls the reed. IDK if there is a 1 to 1 correspondence of the reed frequency and the air column frequency, but it’s reasonable to assume there is some relation, it certainly feels like it. If the reed is vibrating “close enough” to the necessary frequency to create a given note or partial, once the column is in motion it brings the reed into the correct frequency by sympathy. If they are completely at odds you’d get a squeak or nothing. If they are fighting you get poor response.
Reed itself: Think about strings first. Thick strings are less flexible than thin ones so, when sounding a note they have fewer partials present. They sound dark or dull. Thin ones are flexible so they produce a lot of overtones and sound bright. You can produce better overtones by harmonics on thin strings than thick ones (although higher tension also makes it harder). Likewise, the thick part of the reed resists change and resists higher partials, while the thin part is more flexible. Also the longest part of the reed produces lower frequencies, because it’s long, while the shorter part produces higher frequencies - even though the whole reed is always moving.
So, it seems reasonable to assume that, for the most part, lower air column frequencies are created by, and in turn affect the whole vamp, while higher frequencies interact more with the tip. This seems to agree with experience. It also seems reasonable that certain partials interact with certain places on the reed more than others (depending on mouthpiece and cut). Hence, those reed adjustment charts.
However it seems unlikely that overtones in the reed play a large role in controlling the HEARD overtones of the column, or “overblowing”. 1. Because we don’t move our lips back and forth on the reed all the time - even if it’s possible to do it when you try. 2. And because the column has so much more force than the reed. For example clarinet reeds and saxophone reeds are more or less interchangeable if they fit, However a clarinet will never produce the odd harmonics no matter what you do to the reed. Also the normal way of producing harmonics is through voicing, register keys, or odd fingerings. So the column is clearly controlling “overblowing”, not the reed.
Nevertheless, the column “wants” the reed to do something, and the more easily the reed complies the more responsive the instrument is. Effectively, if the reed/mouthpiece combo are fighting with the air column it’s harder to overblow.
That said, the reed cut and strength does seem to have a profound effect on the “unheard” partials, and thus the timbre. And, it seems that some cuts make it easier to overblow, not by controlling the column, but by matching the tendencies of the column. My guess is that the nodes of the reed move along the reed in response to the player/air column, and are not in one specific place, as the way reed as a whole changes its vibration and interacts with the mouthpiece.
- Matthew Simington
Post Edited (2020-11-09 09:04)
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The Clarinet BBoard
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