As evidence mounts that we're somehow hard-wired to be musical, some thinkers are turning their attention to the next logical question: How did that come to be? And as the McGill University neuroscientist Daniel Levitin writes in his just-published book, "This is Your Brain on Music," "To ask a question about a basic, omnipresent human ability is to implicitly ask questions about evolution."

I almost bought this book two weeks ago. I still may. It definitely seemed worth the read; it's a question of time.