This paper presents an approach for determining the similarity between geometrically represented polyphonic patterns. This approach uses a proximity graph representation of polyphonic music from which these patterns are extracted. The extracted patterns then have an outline constructed around them and pattern similarity is determined by finding the maximal overlap of these outlines and determining the ratio of the intersection of the outlines to their union. A graph is constructed by first representing music notes as line segments on a Cartesian plane. Polygons are placed around each line segment; these polygons are used to identify nearby notes, i.e., those located within the polygon. All notes are represented as nodes in a graph; two notes are joined via an edge if they occur within the same polygon. The extracted patterns (defined as paths of length n in the graph) are used to determine the similarity between works of music. This approach yielded positive results, and further work is required to determine its effectiveness on a larger and more varied dataset.