The influences of progression type and distortion on the perception of terminal power chords

The purpose of this study was to investigate the tonal perception and restoration of thirds within power chords with the instruments and sounds idiosyncratic to the Western rock/pop genre. Four separate chord sequences were performed on electric guitar in four versions; as full chord and power chord versions as well as under both clean-tone and distortion effect versions. Undergraduate music majors (N = 50) listened to all 16 chord progressions and rated their perception of the tonality ('majorness' or 'minorness') in the terminal chord for each sequence, utilizing a 7-point semantic differential scale ranging from minor (1) to major (7) with a neutral indicator located in the middle (4). Participants had completed a mean 3.82 (SD = 0.66) semesters of ear training and 28 indicated they played the guitar. A three-way repeated measures ANOVA revealed significant differences between responses for chord sequences (1-4), as well as a significant interaction between chord sequences, distortion (clean versus distortion), and type of chords in the progression (whole chords versus power chords). Further analysis of data indicated that participants tended to perceive terminal power chords as major, especially when progressions were comprised of power chords and contained distortion.