Ha - that neat little music video is good marketing. I'm half tempted to try the book based on that. The only thing really stopping me is that I hate dynamically typed languages, but still I wonder if I shouldn't try Lisp just to "complete my education".
Be aware that SBCL does pretty good compile-time type checking. It helps a lot during dev. And there's the new https://github.com/coalton-lang/coalton to have like Haskell atop CL.