Frank Zappa 1977: "They will pull back the curtains"

Apparently the source of the often seen meme quote from Frank Zappa:

> I would say the illusion [of freedom] will continue as long as it's profitable to continue the illusion. At the point where the illusion becomes too expensive to maintain they will just take down the scenery, they will pull back the curtains, they will move all the tables and chairs out of the way, and you will see the brick wall at the back of the theatre.