One of his projects was called "Nancy Grows Up," in which he recorded audio of his daughter from the time she was born until she was in her teen years, and then compiled it into one continuous track that expresses her development. It is stunning. You can listen to it here.
You can also hear a radio program about Schwartz here.
Schwartz is probably most famous for this crazy, now infamous, "Daisy Ad" made for Lyndon Johnson's 1964 re-election campaign:
But I also like this ad he did against Spiro Agnew: