Written by an avant-garde musician, this book confirms the typical critical attitude of the musical avant-garde towards classical theories. But it must be immediately said that the book does not deal with Theory of Harmony but only with Harmony. It is about the concept that in the field of music theory and didactics is used as an implicit foundation for so many behaviours and precepts. In these pages we do not analyse the musical mechanisms but the conceptual mechanisms. It examines whether the preceptual discourse in music is meaningful or not, and what contradictions and consequences it entails. The essay, written in the form of thoughts, phrases, aphorisms, often crosses over into existential fields and is undoubtedly the testimony of a situation into which we are ourselves drawn.