Neurobiological Foundations for the Theory of Harmony in Western Tonal Music

Abstract

Basic principles of the theory of harmony reflect physiological and anatomical properties of the auditory nervous system and related cognitive systems. This hypothesis is motivated by observations from several different disciplines, including ethnomusicology, developmental psychology, and animal behavior. Over the past several years, we and our colleagues have been investigating the vertical dimension of harmony from the perspective of neurobiology using physiological, psychoacoustic, and neurological methods. Properties of the auditory system that govern harmony perception include (1) the capacity of peripheral auditory neurons to encode temporal regularities in acoustic fine structure and (2) the differential tuning of many neurons throughout the auditory system to a narrow range of frequencies in the audible spectrum. Biologically determined limits on these properties constrain the range of notes used in music throughout the world and the way notes are combined to form intervals and chords in popular Western music. When a harmonic interval is played, neurons throughout the auditory system that are sensitive to one or more frequencies (partials) contained in the interval respond by firing action potentials. For consonant intervals, the fine timing of auditory nerve fiber responses contains strong representations of harmonically related pitches implied by the interval (e.g., Rameau's fundamental bass) in addition to the pitches of notes actually present in the interval. Moreover, all or most of the partials can be resolved by finely tuned neurons throughout the auditory system. By contrast, dissonant intervals evoke auditory nerve fiber activity that does not contain strong representations of constituent notes or related bass notes. Furthermore, many partials are too close together to be resolved. Consequently, they interfere with one another, cause coarse fluctuations in the firing of peripheral and central auditory neurons, and give rise to perception of roughness and dissonance. The effects of auditory cortex lesions on the perception of consonance, pitch, and roughness, combined with a critical reappraisal of published psychoacoustic data on the relationship between consonance and roughness, lead us to conclude that consonance is first and foremost a function of the pitch relationships among notes. Harmony in the vertical dimension is a positive phenomenon, not just a negative phenomenon that depends on the absence of roughness-a view currently held by many psychologists, musicologists, and physiologists.

Functional specializations for music processing in the human newborn brain

“…The perception of sensory dissonance is a function of the physical properties of auditory stimuli, as well as those of basic physiological and anatomical constraints, resulting from limitations of the auditory system in resolving tones that are too proximal in pitch (54). This phenomenon is independent of specific experience and is observable across species (55,56). Although the specific weighting of genetic and experiential factors in shaping early sensitivity to consonance and dissonance remains to be specified, our results indicate sensitivity of the auditory cortex to consonance and dissonance already at birth.…”

Rippling Codes of Event Sequences

“…Кроме того, имеет значение гармоническая связанность высоты тонов нот, как основной энергетической составляющей в музыке. В противном случае, для несогласованных нот парциалы, интерферируя друг с другом, вызывают грубые флуктуации в активности периферических и центральных слуховых нейронов и производят ощущение резкостей и диссонанса [4].…”

“…Исследования в области музыкальных и речевых способностей восприятия в последние годы получили широкое развитие [4,[13][14][15]. Одна из наиболее интересных проблем здесь связана с синтаксисом.…”

Harmony perception and regularity of spike trains in a simple auditory model

“…Complex tones evoke pitch sensations which are often determined exclusively by overtones. However, how the brain estimates the pitch of complex sounds, formed by a combination of pure tones, remains a controversial issue [11] - [14]. Another important quantity in music is the pitch salience, which represents the evidence of the periodicity of some spike train, being the pitch value the periodicity itself.…”

“…Moreover, many partials are too close together to be resolved. Consequently, they interfere with one another, cause coarse fluctuations in the firing of peripheral and central auditory neurons, and give rise to perception of roughness and dissonance [11].…”