R esearch on rock harmony accords with common practice in guitar playing in that power chords (fifth interval) with an indeterminate chord quality as well as major chords are preferred to more complex chords when played with a distorted tone. This study explored the interrelated effects of distortion and harmonic structure on acoustic features and perceived pleasantness of electric guitar chords. Extracting psychoacoustic parameters from guitar tones with Music Information Retrieval technology revealed that the level of distortion and the complexity of interval relations affects sensorial pleasantness. A listening test demonstrated power and major chords being perceived as significantly more pleasant than minor and altered dominant chords when being played with an overdriven or distorted guitar tone. This result accords with musical practice within rock genres. Rather clean rock styles such as blues or classic rock use major chords frequently, whereas subgenres with more distorted guitars such as heavy metal largely prefer power chords. Considering individual differences, electric guitar players rated overdriven and distorted chords as significantly more pleasant. Results were ambiguous in terms of gender but indicated that women perceive distorted guitar tones as less pleasant than men. Rock music listeners were more tolerant of sensorial unpleasant sounds.

W e investigated perception of virtual pitches at missing fundamentals (MFs) in musical chords of three chromas (simultaneous trichords). Tone profiles for major, minor, diminished, augmented, suspended, and four other trichords of octave-complex tones were determined. In Experiment 1, 40 musicians rated how well a tone went with a preceding chord; in Experiment 2, whether the tone was in the chord. Mean ratings for nine non-chord tones were compared with predictions of four models: MFs, diatonicity, 5th-interval relations, and tones that complete familiar tetrachords (e.g., 7th chords). Profiles were accounted for by all four models in Experiment 1, and two (MFs, 5th relations) in Experiment 2. Overall, effect size was largest for MFs. In Experiment 3, listeners heard a chord and chose a matching tone from 12 possibilities. Profile peaks were predicted by pitch models (usually, the lower tone of a perfect 5th). Participants who more likely attended to MFs in isolated harmonic complex tones (fundamental listeners) were not more sensitive to MFs in chords, suggesting their responses instead depended on statistical properties of familiar music. We propose a speculative, psychohistoric explanation: MFs influenced the historical development of musical structure, which in turn influenced the perception of enculturated modern listeners.

A cochlear implant (CI) restores hearing for profoundly deaf patients by transmitting sound to an array of electrodes that stimulates the inner ear. The small number of frequency bands and limited transmission of temporal fine structure affects the music perception. The present work investigates the pleasantness of chords and chord sequences in adults using such electric hearing. In the first task, participants compared chord types according to their perceived pleasantness. Normal-hearing listeners judged the major chord and the minor chord as the most pleasant ones compared to other chord types. CI users appraised the major chord as more consonant than other chord types. The second task used four-chord sequences, half of which ended on an authentic V-I cadence. In the other presentations, the final tonic was replaced either by a transposed major chord or by a dissonant chord. The participants had to judge whether the ending was conclusive. While normal-hearing listeners preferred authentic cadences, all but one CI user assessed the modified cadences as similarly satisfying. The results indicate that CI users appreciated consonance of isolated chords to a certain extent similar to normal-hearing listeners. Nevertheless, the majority of CI users fail to register the musical syntax in the harmonic progression of cadences.

The importance of harmony perception in understanding tonal melodies has been extensively studied, but underlying processes of implied harmonic perception remain unexplored. This study explores how listeners perceive implied harmony in real-time while hearing tonal melodies by addressing two questions: How is each tone of a tonal melody harmonically interpreted and integrated into the previous tones? How do harmonic expectations of “what” chord will follow and “when” the chord change will occur affect the processing? Participants with music training listened to tonal melodies and responded to target tones by singing their pitches as quickly as possible. The target tones implied an expected or an unexpected chord; they occurred at expected or unexpected times. The results showed that sing-back reaction times (RTs) were shorter for: 1) tones implying an expected chord; and 2) chord changes occurring at expected times, suggesting that harmonic expectations facilitate the processing of tonal melodies. Also, RTs became shorter over the presentation of successive target tones implying the same chord, suggesting that implied harmony becomes clearer as more tones belonging to a single chord are presented.

Guitar distortion used in rock music modifies a chord so that new frequencies appear in its harmonic structure. A distorted dyad (power chord) has a special role in heavy metal music due to its harmonics that create a major third interval, making it similar to a major chord. We investigated how distortion affects cortical auditory processing of chords in musicians and nonmusicians. Electric guitar chords with or without distortion and with or without the interval of the major third (i.e., triads or dyads) were presented in an oddball design where one of them served as a repeating standard stimulus and others served as occasional deviants. This enabled the recording of event-related potentials (ERPs) of the electroencephalogram (EEG) related to deviance processing (the mismatch negativity MMN and the attention-related P3a component) in an ignore condition. MMN and P3a responses were elicited in most paradigms. Distorted chords in a nondistorted context only elicited early P3a responses. However, the power chord did not demonstrate a special role in the level of the ERPs. Earlier and larger MMN and P3a responses were elicited when distortion was modified compared to when only harmony (triad vs. dyad) was modified between standards and deviants. The MMN responses were largest when distortion and harmony deviated simultaneously. Musicians demonstrated larger P3a responses than nonmusicians. The results suggest mostly independent cortical auditory processing of distortion and harmony in Western individuals, and facilitated chord change processing in musicians compared to nonmusicians. While distortion has been used in heavy rock music for decades, this study is among the first ones to shed light on its cortical basis.

Probabilistic models have proved remarkably successful in modeling melodic organization (e.g., Huron, 2006a; Pearce, 2005; Temperley, 2008). However, the majority of these models rely on pitch information taken from melody alone. Given the prevalence of homophonic music in Western culture, however, surprisingly little attention has been directed at exploring the predictive power of harmonic accompaniment in models of melodic organization. The research presented here uses a combination of the three main approaches to empirical musicology—exploratory analysis, modeling, and hypothesis testing—to investigate the influence of harmony on melodic behavior. In this study a comparison is made between models that use only melodic information and models that consider the melodic information along with the underlying harmonic accompaniment to predict melodic continuations. A test of overall performance shows a significant improvement using a melodic-harmonic model. When individual scale degrees are examined, the major diatonic scale degrees are shown to have unique probability distributions for each of their most common harmonic settings. That is, the results suggest a robust effect of harmony on melodic organization. Perceptual implications and directions for future research are discussed.

psychoacoustic theories of dissonance often follow Helmholtz and attribute it to partials (fundamental frequencies or overtones) near enough in frequency to affect the same region of the basilar membrane and therefore to cause roughness, i.e., rapid beating. In contrast, tonal theories attribute dissonance to violations of harmonic principles embodied in Western music. We propose a dual-process theory that embeds roughness within tonal principles. The theory predicts the robust increasing trend in the dissonance of triads: major < minor < diminished < augmented. Previous experiments used too few chords for a comprehensive test of the theory, and so Experiment 1 examined the rated dissonance of all 55 possible three-note chords, and Experiment 2 examined a representative sample of 48 of the possible four-note chords. The participants' ratings concurred reliably and corroborated the dual-process theory. Experiment 3 showed that, as the theory predicts, consonant chords are rated as less dissonant when they occur in a tonal sequence (the cycle of fifths) than in a random sequence, whereas this manipulation has no reliable effect on dissonant chords outside common musical practice.

Even adults without formal music training have implicit musical knowledge that they have acquired through day-to-day exposure to the music of their culture. Two of the more sophisticated musical abilities to develop in childhood are knowledge of key membership (which notes belong in a key) and harmony (chords and chord progressions). Previous research suggests sensitivity to key membership by 4 or 5 years, but provides no behavioral evidence of harmony perception until 6 or 7. Thus, we examined knowledge of key membership and harmony in 4- and 5-year-old children using a simple task and a familiar song. In line with previous research, we found that even the youngest children had acquired key membership. Furthermore, even 4-year-olds demonstrated some knowledge of Western harmony, which continued to develop between 4 and 5 years of age. In sum, our results indicate that harmony perception begins to develop earlier than has been previously suggested.