dwturducken is correct about the licensing.
I had a similar moment of questionable sanity several years ago, just a few months after launch, when I heard the same music being played over a bumper in the Ellen show.
I was initially excited, as I thought Ellen was about to feature the game.
Alas, after some research, I learned that the stiff was just licensed 'from the wild' as you say.
It appears that a lot of the initial music was done this way.
I'm not sure how long that continued though....