If I asked you to think of any movie or recording from the early 1900s you would likely think the same as me: something with a lot of grain or muffled sound. Then I came upon this post from Dave Rahardja over on Mastodon.
These carbon microphones are incredible because you have @Samsonite1890 performing Five Foot Two on the banjo here in 2024 and yet it sounds perfectly like a recording a century ago. Originally developed in 1878 by David Hughes in England, the device used loosely packed carbon granules and the varying pressure exerted on the granules by the diaphragm from acoustic waves caused the resistance of the carbon to vary proportionally. This allowed a relatively accurate electrical reproduction of the sound signal. Hughes also coined the word microphone.
While Thomas Edison and Emile Berliner also independently developed this technology, Hughes decided not to take out a patent; instead, he made his invention a gift to the world according to Wikipedia. Here in the US, Edison fought and won the patent, because of course he did.
The video should play in Dave's embedded post above, but the original TikTok is below. You can also directly access it here.