1. A method for determining a similarity of a target music collection and a reference music collection with respect to a specific user, comprising: comparing metadata associated with the target music collection and metadata associated with the reference music collection using a plurality of comparison algorithms including at least one comparison algorithm based on acoustic metadata and at least one comparison algorithm based on cultural metadata, each comparison algorithm producing a result automatically developing a basis vector from a basis set, the basis set including a plurality of audio tracks representative of the specific user's musical preferences, the basis set being all or a portion of the specific user's music collection, wherein automatically developing the basis vector comprises: comparing each track in the basis set to each other track in the basis set using each of the plurality of comparison algorithms averaging the results for each comparison algorithm scaling the averaged results to form the basis vector weighting the results of the two or more comparison algorithms using the basis vector combining the weighted results of the two or more comparison algorithms.