Thanks to the proliferation of easy accessible audio editing software and its ability to edit music, we are seeing mashups of songs that just a few years ago we were not able to be created by hobbyists.
For today we have two artists on the polar opposite sides of the music spectrum with the Deftones and Britney Spears. The music is one of the Deftones' most popular songs "Change (in the House of Flies)" but the lyrics have been stripped off and instead Britney Spears' "Toxic" takes over for Chino Moreno.
I'm by no means a musician but since the two songs I think are in the same key... it works. The outcome is making me think that this could actually be a real song and that Britney should start a metal band to bring in a whole new fanbase.