Found this Q in a cymatics article

>https://www.businessinsider.com/water-slow-motion-video-standing-waves-cymatics-2018-5?fbclid=IwAR1biymZgA-39Glb3Zru7jSIUPMeVZ8FBMnob0EoBatO9TSRbt4OGFfad4c#gledhill-also-used-square-dishes-to-create-cymatic-images-this-one-became-a-music-album-cover-12