Modeling and Perception of Melodic Contour Families

Pitch contour is a defining feature of individual melodies and also melodic families, which are important for motivic development. Previous studies show that listeners are sensitive to melodic contour, and music theorists have created mathematical models of contour similarity. However, this research has compared only melodies with the same number of notes, even though melodic families often include longer and shorter members. A recent music-theoretical model by Wallentinsen (2022) overcomes this limitation, using fuzzy set theory to account for familial relationships among contours with varied lengths. We conducted three experiments where participants heard a family of six reference melodies followed by one test melody. They judged the test melody as same or different from the reference family (Experiment 1) or rated its similarity to the reference family (Experiments 2 and 3). We varied the number of contour changes and, in Experiment 3, the melodies’ length. Listeners were accurate and consistent in their judgments of contour similarity and family membership, and Wallentinsen’s model predicted their ratings of family membership. These results suggest that listeners attend to similarities in contour and can group melodies into families despite variations in melodic cardinality.