我觉得这个问题最好在读这书之前就搞清楚。 太多人觉得这书在玩文字游戏，故弄玄虚。天大的冤枉啊，无论是Bach还是escher， 其实都是用来解释书中概念的analogy. 下面是作者接受wired的采访时说的，标题就叫“by analogy":
I can see that many people didn't understand what the book was trying to do. Many people took it to be nothing but a title. They would look at the three words - Gödel, Escher, Bach - and if they knew who these people were, they'd say, Oh, this is a book about mathematics, art, and music.
What Gödel, Escher, Bach was really about - and I thought I said it over and over again - was the word I. Consciousness. It was about how thinking emerges from well-hidden mechanisms, way down, that we hardly understand. How not just thinking, but our sense of self and our awareness of consciousness, sets us apart from other complicated things. How understanding self-reference could help explain consciousness so that someday we might recognize it inside very complicated structures such as computing machinery. I was trying to understand what makes for a self, and what makes for a soul. What makes consciousness come out of mere electrons coursing through wires.
And yet many people treated the book as just some sort of big interdisciplinary romp whose point was simply to have fun. In fact, the fun was merely icing on the cake. Originally, the book was purely about the way the proof of Gödel's theorem kept cropping up in the middle of a fortress - Principia Mathematica by Bertrand Russell and Alfred North Whitehead - that was designed to keep it out. I thought, Here's a structure that attempts to keep out self-knowledge, but when things get sufficiently complex and sufficiently tangled, all of a sudden - whammo! - it's got self-representation in it. That to me was the trick that underlies consciousness.
So, at first, there were no dialogs, no jokes, no wordplay, and no references to Escher or Bach. But as I typed the manuscript up in '74, I decided it was written in an immature style. I decided to insert the dialogs and the Escher so that the playfulness became a kind of a secondary - but extremely important - part of the book.
Many people focused on those things and treated the book as a big game-playing thing. I had been aiming to have the book reach philosophers, people who thought about the mind and consciousness, and a small number actually saw what I was getting at, but most people just saw the glitter. At the time, I felt I'd lost a great deal by writing a book like that so early in my career, because I was no longer taken seriously by anybody. http://www.wired.com/wired/archive/3.11/kelly.html
他说整本书讲的是 “意识”，self-reference 怎么形成 意识。尽管音乐和艺术部分很有趣，不过绝不是核心。
PS 我觉得这本书应该先看一遍了解核心内容, 然后再仔细看它奇妙的形式, 对话形式与其内容的一致.