So, I treked up the hill to find a good place to take a clean shot. I ended up right next to the South San Francisco "Wind Harp"
This thing is a 90' high sculpture on the top of a hill. It is an Aeolian Wind Harp and more info can be found at this web site
It makes a truly odd, but very subtle sound. The website above has an "ogg" file that tries to capture the sound, but it can't because of the sound of the wind itself.