You can find the Aeolian harp by Douglas Hollis at the bay end of pier 15. It's one of the Exploratorium's outdoor exhibits free to the public. For more info see: Jesse Hamlin "Harp sings in the wind", San Francisco Chronicle April 21, 2013. I used a ZOOM H2 Handy Recorder on a pole held close to the center of one of the horns to record the sound. Unfortunately the horns are too high to put your ear next to them and there is usually too much extraneous noise to hear clearly by standing in front.