The focus of this paper is the exploration of ontologies as a means for knowledge sharing in music information retrieval scenarios. Our approach is intended to support the complete "life cycle of digital music" and focuses on the implications of a digital world for all the actors involved in the process of creation, consumption and modification of such entities. As a novelty we take care about legal aspects, digital rights management being heavily tangled in such scenarios. MPEG-7 and MPEG-21 vocabularies are considered as basic ingredients for our ontology which ensures in this way interoperability within the multimedia delivery and music research communities.