This past weekend, the National were in Austin, Texas for the Austin City Limits festival, and they also played an aftershow at the local venue Stubb’s. Bon Iver frontman Justin Vernon, who had just played with his blues-rock side project the Shouting Matches, joined the band onstage for two songs, singing and playing guitar on “Terrible Love” and then joining in on a cathartic singalong of “Vanderlyle Crybaby Geeks.” Both of those songs come from the National’s 2010 album High Violet, which featured Vernon’s backing vocals. Watch two fan-made videos below.

You have to like Vernon’s deeply unassuming background-singer demeanor.