Enhanced Multimedia Meta Objects (EMMOs) are a novel approach to multimedia content modeling, combining media, semantic relationships between those media, as well as functionality on the media, such as rendering, into tradeable knowledge-enriched units of multimedia content. For the processing of EMMOs and the knowledge they contain, suitable querying facilities are required. In this paper, we present EMMA, an expressive query algebra that is adequate and complete with regard to the EMMO model. EMMA offers a rich set of formally-defined, orthogonal query operators that give access to all aspects of EMMOs, enable query optimization, and allow the representation of elementary ontology knowledge within queries. Thereby, EMMA provides a sound and adequate foundation for the realization of powerful EMMO querying facilities.