I found this really cool music site, Wolfgang's Vault, by accident. The owner of the site purchased certain assets of Billy Graham, the concert promoter, and has been streaming audio from the concert venues. I read about the lawsuit that these artists have filed against him, and it made me curious.
With the advent of YouTube, there is a plethora of old music to view. But, sometimes when working, the "viewing" part is difficult, and all you really want to do is "listen" to the music. This site is awesome, if you are looking for lots of vintage rock concert audio. Registration is free, and the eclectc mix of music is great when you need a break from YahooMusic or AOL Music or Sirius or whatever.