Frank Zappa: Portrait of the Artist as a Businessman, by Rob Partridge and Paul Phillips, Cream, 1972. Courtesy once again of afka.net.
Frank discusses the business side of things. He was certainly a much savvier and more thorough businessman than most rock artists, then or now -- but his comments about what a good deal he has with Warner Brothers are an indication that he still had some hard lessons left to learn; he'd be singing a much different tune a few years later.