The clip was filmed in 1988 for a music video, while the band were still going by the name of Ted Ed Fred.
Frontman Kurt Cobain can be seen leaping into the frame several times to join bassist Krist Novoselic and Melvins drummer Dale Crover.
Video archivist Mike Ziegler posted the footage, which was shot at a RadioShack in Aberdeen, Washington, on YouTube.
The long-lost recording shows Cobain and Novoselic lip syncing and pretending to play their instruments while Crover performs live.
At one point they even experiment with smoke to inject some stage magic.
RadioShack is an American chain of electronics stores – not where you’d expect to find rock stars in the making.
Ziegler also uploaded another video of the band members playing around with plasma globes in a dark closet at the same shop, presumably as part of the music video.
Even though it was early days in their career, you can see the band’s raw talent shining through.