You probably saw this, but there was recently a surprisingly good Google doodle that used AI to generate harmonies in the style of Bach (two bars at a time). Here's Bach doing Beethoven. And an especially fancy version of I Like Meow Mix.
In one episode of 30 Rock, you can vaguely hear a Joni Mitchell parody. Here it is
jwz recently found out that Netscape and its patents (but not the name) belongs to Facebook.