Miller's newest book - A Million Miles in a Thousand Years - covers this in more detail.
Pardon me while I break off to go edit my life.
You see, this book is (ostensibly) about the process of turning Jazz into a movie. Two filmmakers come calling, Miller agrees to have his life scripted for the screen, and the three men collaborate on a screenplay. It's a chance for Miller to "edit his life," to make it more structured, compelling, and, well, movie-like. Does his life, like Casablanca, have purpose in every scene and every line of dialogue? Will his life leave observers with a beautiful feeling as the credits roll?
These questions stand at the heart of A Million Miles in a Thousand Years, which is essentially a stream-of-consciousness meditation on story, how our lives are like stories, the theory of narrative, God as a writer, and so on. It's a movie-like book about a book becoming a movie. The prose alternates between episodic, cinematic "scenes" and philosophical ruminations about story. It's all very meta and postmodern and layered in an Adaptation sort of way.