Open two tabs. In the first tab, type this URL into the address bar:
In the second tab, type this into the address bar:
What should come up is my instrumental playlist, on my MuffinRuler15 account.
Go to track 2: Opus 23, and pause it at 3:15.
Go back into the first tab and press play on the video, immediately clicking it onto mute. Quickly go back to the second tab and press play on the Opus. Then go back and watch the video with it's new soundtrack.
The result should be amusing for at least 3 minutes.
What if every morning you woke up and watched video's of people doing yoga? To music?