[Harp-L] Re: The Reason that Overbends Work

[Steve Baker <steve@xxxxxxxxxxxxx>]

I don't believe it's a question of which point on the reed the airflow is "focussed" on, airflow doesn't work like that. However, the reason for the pitch difference may be that when the reed is opening it's effectively slightly shorter due to the fact that it's attached to the side of the reed plate away from where the airflow is coming from, so its pitch is slightly higher. Interesting discussion, thanks.

On 23.09.2014, at 20:09, Harmonicology [Neil Ashby] wrote:

> My theory pertaining to the overbend note being naturally higher is as follows: Use for example the draw reed and to cause the closing of the draw reed then the user is lowering the air pressure on the side of the reed-plate away from the rivet; the result is that the reed is actually pushed into the slot via the higher air pressure which is evenly spread across the side of the reed having the rivet; in the case of the overblow on the same reed then the air-flow is focused at the tip of the reed at the point that the reed is recessed into the slot and thus the air-pressure is focused into some small wedge-shape between the reed-tip and the slot; because the air-pressure is focused at that small area then the reed vibrates as though it would be some shorter reed.
> 
> /Neil Ashby II (" https://www.facebook.com/profile.php?id=100004575466934 ")
> 

Steve Baker
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