An old friend of Kurt Cobain named John Purkey has just posted some old demos of Nirvana.
Purkey posted the audio on his Youtube channel called The Observer. The four videos contain cassette recorded audio of Nirvana demos from the late 80s. Purkey claims that the tapes were given to him by Cobain himself.
The tapes amount to about two hours of material, some that has been heard before. Former drummers Dave Crover and Chad Channing are on these recordings.