Morphing-based Reharmonization with VAE: Reducing Dissonance with Consonance-based Loss Function

This study proposes a model to reduce dissonant chords in morphing-based reharmonization using a variational autoencoder (VAE). The conventional morphing of chords generates dissonance because the generated results are supplemented by the surrounding learning data in the latent space without considering consonance. Therefore, this study focuses on degrees of dissonance that can be calculated from pitch intervals. We define an ideal consonance degree based on the dissonance degree, and we implement a dissonance penalty as a simple network structure by adding nodes to the VAE so that a co-occurrence vector of pitch interval computed from each chord tone approaches the ideal consonance degree. Our objective evaluation demonstrates that the number of standard triads increased compared to the conventional VAE morphing method when the model was used. In addition, the number of non-standard and dissonant chords decreased through our model.