Exploring Melodic Contour: A Clustering Approach

Previous studies investigating common melodic contour shapes have relied on methodologies that require prior assumptions regarding the expected contour patterns. Here, a new approach for examining contour using dimensionality reduction and unsupervised machine-learning clustering methods is presented. This new methodology was tested across four sets of data — two sets of European folksongs, a mixed-style, curated dataset of Western music, and a set of Chinese folksongs. In general, the results indicate four broad common contour shapes across all four datasets: convex, concave, descending, and ascending. In addition, the analysis revealed some micro-contour tendencies, such as pitch stability at the beginning of phrases and descending pitch at phrase endings. These results are in line with previous studies of melodic contour and provide new insights regarding the prevalent contour characteristics in Western music.