Distortion and Rock Guitar Harmony: The Influence of Distortion Level and Structural Complexity on Acoustic Features and Perceived Pleasantness of Guitar Chords

Research 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.