I’m no expert but I think it has to do with this effect: https://en.wikipedia.org/wiki/Vortex-induced_vibration

See also: https://en.wikipedia.org/wiki/Aeolian_harp

Edit: might be a completely different kind of oscillation than I was thinking of. https://news.sky.com/story/spain-portugal-power-outage-lates...

So I would also like to understand how this works :)