Aerosmith was playing in Phoenix, and tearing through "Walk This Way" and then, out of nowhere, rapper Macklemore shows up, and puts his, um, stank on it. And it stank. To be fair, I'm all for the rock/rap collaborations, Aerosmith and Run-DMC, Anthrax and Public Enemy, Linkin Park, all or it. Just not this time. Enjoy the video, the trainwreck appears at about 2:50.