I upvoted this for the quality of writing and production, not core content (which isn't newsworthy). It's beautifully done (with the accurate animations of gearing) and finds tons of interesting things to talk about and demonstrate.
In theory, I knew how it works. In practice a music box is really a black box that only seems unsophisticated due to marketing and mass production as toys since my childhood.
Every one of The Engineer Guy’s videos are a spectacular insight into the immense complexity of everything around us, and a beautiful demonstration in how to make that complexity both fascinating and understandable. It’s often quite a while between updates, but I highly recommend you subscribe to his channel.