kengr

For that matter they've had t-shirts that have a multicolored active bar graph sound spectrum displays for years now. I think I first saw one at a con 15-20 years back.

Here's one version./ and it's a lot cheaper than I'd expect. Doesn't come in my size, alas

https://www.casesinthebox.com/sound-activated-led-equalizer-t-shirt_p10531.html#description