Abstract: Systems and methods for determining similarity between two or more audio pieces are disclosed. An illustrative method for determining musical similarities includes extracting one or more descriptors from each audio piece, generating a vector for each of the audio pieces, extracting one or more audio features from each of the audio pieces, calculating values for each audio feature, calculating a distance between a vector containing the normalized values and the vectors containing the audio pieces, and outputting a response to a user or process indicating the similarity between the audio pieces. The descriptors can be used in performing content-based audio classification and for determining similarities between music. The descriptors that can be extracted from each audio piece can include tonal descriptors, dissonance descriptors, rhythm descriptors, and spatial descriptors.