"The Disintegration Loops" by William Basinski. The story goes that Basinski took some old tape loops from the 1980s that he had made and was attempting to archive them into a digital format when he noticed that the play head on his tape deck was slowly flaking little bits of information off of the tape. What's heard at first is barely audible by the end of the hour. The archiving took place in his apartment in Brooklyn on the morning of September 11, 2001. Dunno if it's a true story but that's what they say.
YouTube: https://www.youtube.com/embed/qYOr8TlnqsY