When we spoke to Lou Barlow about this month's Dinosar Jr. 30th anniversary concerts at Bowery Ballroom, he suggested there would be special guests but kept relatively mum on who they'd be except to say there would be members of Sonic Youth involved. As the week played out, we saw them do Bug highlight "Don't" with Kim Gordon and collaborate with Kurt Vile. Last night's show featured a searing eight-minute cover of the Neil Young barn burner "Cortez the Killer" with Portlandia star Fred Armisen on a second drum kit behind Murph and ex-Sonic Youth singer-guitarist Lee Ranaldo on vocals. Watch the performance below and enjoy Lee's warm intro about touring America with Dinosaur in 1986. While you're down there, check out a bonus video of Armisen leading the band through a spirited rendition of "Hey Policeman!," a song he wrote and performed as part of the fictional punk rock band Ian Rubbish and the Bizarros.