This work has been incredibly popular in Germany since its first publication in 1981. Its impact was such that it has transcended the academic university and secondary education, where is a reference text to become part of general culture, becoming a bedside book for managers, sales representatives, social workers and teachers, among others.

Through the square model of communication, Friedemann Schulz von Thun shows how all human expression unfolds its energy on four levels: the objective content,'s self, relationship and incitement. The mere knowledge of them will not improve our communication, but if we develop a sensitivity to this "four-note chord," will improve our "musical sense" in terms of interpersonal communication is concerned. This will give us the opportunity to become good composers of music with the sound of our own personality.