On May 9, 1987, Sonic Youth were the surprise guests at a benefit show supporting Jimmy Johnson and Byron Coley’s experimental music magazine Forced Exposure. The concert went down at The Rat in the mag’s home base of Boston, and it featured some serious underground heavy hitters. Forced Exposure contributor Steve Albini was there to introduce Sonic Youth, and noted Massachusettan J Mascis joined them for the second song. On equipment borrowed from Dredd Foole and the Din, SY covered Crime’s “Hot Wire My Heart” with Thurston Moore on lead vocals, followed by the Stooges’ “I Wanna Be Your Dog” as sung by Kim Gordon, who appeared to be vibing out extremely hard throughout. As Brooklyn Vegan points out, previously unreleased footage of this surprise performance has made its way to Sonic Youth’s YouTube account, and I highly recommend you watch it below.