The Significance of the Low Complexity Dimension in Music Similarity Judgements

Previous research has demonstrated that similarity judgements are context specific, as they are shaped by cultural exposure, familiarity, and the musical aesthetic of the content being compared. Although such research suggests that the criterion for similarity judgement varies with respect to the musical style of the content being compared, the specific musical factors which shape this criterion are unknown. Since dimensional complexity differentiates musical genres, and has been shown to affect similarity judgements following lifelong exposure, this experiment investigates the short-term influence of dimensional complexity on similarity judgements. Rhythmic and pitch sequences with two levels of complexity were factorially combined to create four distinct types of prototype melodies. 51 participants rated the similarity of each type of prototype melody (M) to two variations, one in which the pitch content was modified (M̄p), and another in which the rhythmic content was modified (M̄r). The results indicate that rhythm and pitch complexity both play a significant role, influencing the perceived similarity of M̄p, and M̄r. The dimension bearing low complexity information was found to be the predominant factor in similarity judgements, as participants found modifications to this dimension to significantly decrease perceived similarity.