Chicago music fan Aadam Jacobs has been recording concerts since the 1980s, creating an archive of over 10,000 cassette tapes. Now 59, he's working with Internet Archive volunteers to digitize these recordings before they degrade. About 2,500 tapes have been posted online so far, including rare performances by Nirvana from 1989, Sonic Youth, R.E.M., and other influential artists from before they became mainstream.