Rage Against The Machine Vs Pharrell Williams - Happy Bulls on Parade (DJ Errn Mashup) Mash-ups are one of the most exciting parts of being a DJ. They let you take two completely different tracks and combine them in a way that creates something fresh, surprising, and sometimes a little unexpected. One of my favourite experiments recently has been mixing the energy of Rage Against the Machine with the feel-good groove of Pharrell Williams. The result is “Happy Bulls on Parade”