RE: Bends: physics and physical

["Tim Moyer - Working Man's Harps" <wmharps@xxxxxxxxx>]

Okay, well it is true that you can move the straw, and I should have
explicitly said "without moving the straw".  You got me there!  

But if bending were a matter of directing airflow, then it would follow
that it would be possible to bend the upper register reeds (holes 7 and
above) upwards in pitch by redirecting the draw airflow to the blow reeds
which are tuned higher.  What you do see, however, in those upper reeds is
that the blow reeds can be bent down in pitch due to the presence of lower
tuned draw reeds which respond to the resonant lowering of the blow reed
pitch.  

The physical principles on which a two-reed bend occur are well understood,
and some harmonicas, such as the Hohner XB-40 are designed to exploit this.
 The XB uses an additional pair of responder reeds in each chamber to make
it possible to bend the pitch of every note, both blow and draw.  

Thanks for keeping me honest,

- -tim



At 11:02 AM 5/15/04 -0400, Paul Harker wrote:
> 
>From: owner-harp-l@xxxxxxxxxx 
>> On Behalf Of Tim Moyer
>
>> The fact that you can achieve a bend through a soda straw 
>> indicates that angle of airflow isn't a factor.  
>
>I don't believe this is necessarily true. It is very easy to change the
>angle of airflow using a soda straw; just move the straw. I'm assuming
>"without moving the straw" was intended to be implied.
>
>Thanks much for an informative post.
>
>
>
>
Tim Moyer
Working Man's Harps
http://www.workingmansharps.com/