Do you want another video experience? Then the Audio visualizer for YouTube is a new thing you can try. The audio of the current video player will be visible as a signal block diagram or a line.
Turn Off the Lights Browser extension is the only and unique extension that got this feature. It has the option to see a visualization effect of the playing audio file. So you for each beats, a higher block signal.
If you want to get this a try, you can get the Audio visualizer for YouTube by installing this free Turn Off the Lights browser extension.