Melodic Similarity through Shape Similarity

We present a new geometric model to compute the melodic similarity of symbolic musical pieces. Melodies are represented as splines in the pitch-time plane, and their similarity is computed as the similarity of their shape. The model is very intuitive and it is transposition and time scale invariant. We have implemented it with a local alignment algorithm over sequences of n-grams that define spline spans. An evaluation with the MIREX 2005 collections shows that the model performs very well, obtaining the best effectiveness scores ever reported for these collections. Three systems based on this new model were evaluated in MIREX 2010, and the three systems obtained the best results.