Some fantastic footage of John Cage, that most endearingly controversial of avant garde composers, performing one of his pieces (Water Walk) on the American game show "I've Got a Secret" in 1960.
Here's some crazy mashups for my sis. Now them's what I call mashups. You might also enjoy these one minute or less remixes of various songs. My favourite is this version of Stagger Lee by Nick Cave. I also enjoyed Take One (a version of Dave Brubeck's Take Five). Or how about the whole of OK Computer in 45 seconds (wait for the hilarious ending).
Martin Denny performing Quiet Village. Class.
In fact, just go and read this fantastic radio station blog I stumbled across where these and many other nuggets came from.