Eigenpoll : Alternative Science books : Godel, Escher, Bach 

By Douglas Hofstadter
A book that ties together math, art, and music and explores what the author calls "Strange Loops", or self-referental sentences or concepts.

Concepts range from biology, to computers and AI, to Zen, and of course, math, art, and music. Everyone should own this book.

ISBN: 0465026567