The Consonance and the Context Guiding the Participants' Ratings of Chords Representing Different Set-Classes

Abstract

This study examined factors guiding the participants' ratings of pentachords representing different pentad classes. Two tests were carried out where the participants (non-musicians, professional music students, and music theorists and composers) heard sequences of five chords. Four of the chords represented one set-class, and these chords formed the context; one chord represented another set-class, and it was the deviant. The participants were asked which chord did not belong to the same group as the others. When the data were analysed, the main interest was in the difference in the consonances of the context chords and the deviant chord. The difference varied greatly from case to case. It was found that the participants selected the deviant chord when there was a clear difference in the consonances of the set-classes. However, the difference in the consonances was not the only factor guiding the participants' ratings. The context was found to be important for both musically trained and untrained participants, but in different ways. Generally, the non-musicians used the set-class identity as a guide in the items where the context was more consonant than the deviant, while in a dissonant context they used chordal characteristics, especially the transpositional level. The composers and theorists, on the other hand, made their ratings according to the set-class identity when the context was more dissonant than the deviant and according to the chordal characteristics when the context was more consonant than the deviant.