Mike Ziegler is a collector and (apparently) a Nirvana superfan. One website once called him “probably the internet’s most prestigious Nirvana trader of all time.” Ziegler deals in videotapes, pictures, set lists, and other artifacts and ephemera from the time when grunge music was just beginning to form. Just check out his impressive collection of Nirvaniana.

His latest find is a videotape made on January 24, 1988, which shows the now-legendary band performing in an empty RadioShack in Aberdeen, Washington, a day after they recorded their first demo. But the video isn’t a live show, it’s what might happen in any teen’s bedroom at any given moment—a pantomime of rocking out.

As you’ll notice, Kurt Cobain jumps a bunch, and bassist Krist Novoselic also seems to be playing along—but their instruments aren’t plugged in. It’s only the drummer, Dale Crover, best known for playing with the band Melvins, who’s actually making any noise. (Dave Grohl didn’t join them on drums until the next year.) Recorded just a day after a show at the Community World Theater in Tacoma, which Ziegler also uploaded footage of here, this was intended to be a music video “of sorts,” according to Ziegler.

Ziegler doesn’t name the person who shot the film, but says he’s always on the hunt for other recordings.

“If you happen have a Nirvana tape that you recorded that has been sitting in a closet/attic/basement for 25+ years, let me know,” he wrote yesterday. “Happy to help get it properly archived and shared with the world.”

Four years after the video was shot, Nirvana’s Nevermind displaced Michael Jackson’s Dangerous at the top of the charts, paving the way for the band to become, arguably, the biggest rock band in the world. RadioShack didn’t know what they had.