Wind in abandoned fencing-wire as heard by contactmics

This random pile of fencing wire abandoned decades ago is still silvery and un-rusted, but grass and other plants grow through it. In wind it moves as complex interlinked system creating percussive hums from low bass to higher pitches that reverberate inside. Unhearable to the ear, but audible to contact mics. The contact mics are the simplest self made piezos, but using TritonAudio BigAmp Piezo pre-amplifiers, which are very effective. They reveal bass frequencies that previously I had no idea were there.