The long version (possibly more info than you really want from me): today I found an article about the wave organ, on the Mercury News app from the Bay Area News Group. I read the Mercury News every day, although I live on the opposite coast, because they publish several advice columns I like. The article included a video, but because the iPad Mini 2 I use with the app is ancient (2013), the video wouldn't play. So I looked it up on YouTube and found this one (same link as I included in the tweet). It told and showed me what I wanted to know, in a manageable package. When I tried another method of viewing the Mercury News video, I found that it was 40 minutes long, which is more than my attention span can handle right now. Please enjoy this lovely video. It will only take up three minutes of your time! If you happen to be desperate for more time fillers, check out the 40-minute one and let me know how it was.
Here’s the explanation from the Exploratorium, the “public learning laboratory exploring the world through science, art, and human perception” that originated the project. (Poke around their website to learn about lots of other stuff!). And here’s an Atlas Obscura article about the wave organ.