They call it a “mashup” -- blending two or more pre-existing recordings to create a new one, usually by laying the vocal track of one song seamlessly over the instrumental track of another. This is a case in point, using Van Halen singing "Jump" and John Lennon playing "Imagine." Hard to believe (or maybe, hard to imagine), but this sort of thing can actually qualify for the "fair use" provisions in copyright law. We have “Mighty Mike” to thank for doing a better job of ruining this song, than that guy we've never heard of who changed the lyrics on New Year's Eve. Atta boy, Mikey!
And so, the tradition continues for another year, with this week's Friday Afternoon Moment of Whimsy.