He talks about John Lennon's Imagine and why it is actually such a terrible song. It's really a song about a utopia of nothingness - a place where people give up all their things and their beliefs so there is nothing to talk about, nothing to live for, nothing left to fight over, etc.
I used to love that song, but I have come to realize that it really is Lennon's way of describing a very ugly and gray world. We can never get to that world and we should never want to. Please watch it!