Odd harmonics: see it and hear it

[hare.29]

Here's something I was just playing around with that some people might find interesting:

It's a middle A held to feedback.

It sounds like:

http://s11.yousendit.com/d.aspx?id=1Z0S8Z3SFB7D4307TL4L194CY8

(414Kb file)

 

It looks like:

You can see the even harmonics die away and the odd harmonics grow into the feedback. And I need a better mic.