“Trainwreck 1979,” the first single from Death From Above 1979’s seething reunion album The Physical World, is an absolute drooling monster of a song, a piece of music so hard that it’s hard to believe two dudes made it. And when the band appeared on the Late Show With David Letterman last night to perform the song, they probably didn’t need help, but they had it anyway. Paul Shaffer and his band backed the band up on the song, thus marking the first time you’ve ever seen a motherfucker playing flute on a DFA1979 song. You might expect this to detract from the rawness, but it didn’t really happen. The song still slammed. Watch the performance below.