Tonight, two former R.E.M. members, Mike Mills and Peter Buck, will be on the Late Show With David Letterman. They’re backing up the night’s musical guest, singer-songwriter Joseph Arthur. Letterman tapes his show early in the day, which means those guys were on hand for something of a landmark show-business moment: Apparently, David Letterman is retiring. We only know this, though, because Mills tweeted it, effectively breaking the news. Here’s Mills: “Dave just announced his retirement #2015 #muchlovedave.”

Below watch R.E.M. playing Late Night With David Letterman in October ’83. It was the band’s first television performance and “So. Central Rain” didn’t even have a name yet…

UPDATE: Here’s Letterman’s announcement followed by a short backstage interview in which Mills explains why he broke the news over Twitter.