The Tritone Paradox

Chapter 5 explores the tritone paradox—a musical illusion that was discovered by the author. Its basic pattern consists of two computer-generated tones that are related by a half-octave (i.e., a tritone). These tones are well defined in pitch class (note name) but ambiguous in pitch height. When one of these tone pairs is played in succession, some people hear an ascending pattern, yet other people hear a descending one. Indeed, a group of people will disagree completely among themselves as to whether such a pair of tones is moving up or down in pitch. Furthermore, any one person hears one of these tone pairs as ascending or descending depending on their note names (such as C–F♯, or G♯–D). How people hear the tritone paradox varies with the geographic location in which they grew up—and so with their native language or dialect. Native English-speaking Californians hear this pattern differently from natives of the south of England. People who are natives of Vietnam hear the pattern quite differently from native English-speaking Californians. The tritone paradox shows, therefore, that the way we perceive music is related to our language, and generally reveals strong effects of our memories and expectations on how we hear music. It also has important implications for absolute pitch (or “perfect pitch”)—the rare ability to name a musical note that is presented in isolation. People make orderly judgments of the tritone paradox, even though they cannot name the notes that they are judging, so they must have an implicit form of absolute pitch.