////I don't recall anything about Atlantis... What's the title of the one you mean?/////

"The Pythagorean Plato--Prelude to the Song Itself" by Ernest G. McClain. It examines not only Atlantis but The Republic and Timaeus. He ties music theory into everything mentioned in these works. You have to know your music theory and your Plato. Extremely interesting book but not the easiest to get through. The stuff I've been talking about is pretty elementary but this book is definitely a higher level.