There are embedded YouTube videos, MP3s, and code samples to illustrate what he's writing about. He's implemented their ideas using the Web Audio API and you can run the code from within the page and listen to the music being generated in real-time. It's a real testament to how great the web can be.
I think being able to do things like that is worth all the annoying parts of the modern web, in the end. For the developer and the end user. I wouldn't want to go back to the old way. I think it's easy to focus on the annoying parts and take the good parts for granted.