Bends: physics and physical

[paul-harker@xxxxxxxxxxx]

I'm a harp newbie, and have finally managed to get all the various draw bends. Of course sometimes they are sounds only a mother could love, but a milestone for me never-the-less.

So while I spent those hours trying to evoke a bend, I would ponder what the heck is going on that causes a bend. I understand the sympathetic resonanance of the opposing reed causes the bend, but why are some notes bent, and others bent to varying degrees? I've read some postulation that it has to do with the 'angle of attack' with respect to the reeds. This would be a logical assumption as when a bend is accomplished the airflow is indeed at a different angle. But if the angle is the issue, why can I get bends with the harp rotated to any orientation: rightside up, upside down, vertical, 45 degree etc? Obviously there must be something else. I've also heard theories that the shape of the mouth causes resonant frequencies in the air. This didn't really make a whole lot of sense to me either, but did lead me to my personal theory.

Ok, here it is, my theory on the physics of a bend -- I'd love it if anyone could verify or debunk this with factual studies: 

I believe that an unbent note is the result of the airflow pattern with the least resistance. I.e. the air moves through the harp in a nice smooth path, with has no involvement with the opposing reed.

However, when we bend, we are causing turbulence by inhibiting the path of least resistance, forcing the air to take a higher resistant (i.e. turbulent) path. This turbulence, by it's nature, affects the opposing reed. The amplitude of the turbulence affects the depth of the bend. 

On another note; one thing about bending I noticed is that they require a complex interaction of muscles to be used in manners and positions they may not be able to accomplish due to lack of strength -- at first. So the newbie, such as myself, works and works wondering why those notes are so elusive. The truth is that it's a lot like lifting a weight, you won't be able to do it at all until the requisite strength is built. Had I better understood this, my frustration might have been lessened.

I'm not attempting to minimize the required focus on the technique, it's obviously every bit as essential. Certainly the all-encompassing axiom: Practice, Practice, Practice, is the answer to both. But it helps to know what that practice is going to achieve. Once I realized that muscle strength was a limiting factor, the wisdom of multiple 15-minute practices over a one-hour marathon became very clear. 

 Paul