Discovery of Contrapuntal Patterns

This paper develops and applies a new method for the discovery of polyphonic patterns. The method supports the representation of abstract relations that are formed between notes that overlap in time without being simultaneous. Such relations are central to understanding species counterpoint. The method consists of an application of the vertical viewpoint technique, which relies on a vertical slicing of the musical score. It is applied to two-voice contrapuntal textures extracted from the Bach chorale harmonizations. Results show that the new method is powerful enough to represent and discover distinctive modules of species counterpoint, including remarkably the suspension principle of fourth species counterpoint. In addition, by focusing on two voices in particular and setting them against all other possible voice pairs, the method can elicit patterns that illustrate well the unique treatment of the voices under investigation, e.g. the inner and outer voices. The results are promising and indicate that the method is suitable for computational musicology research.