The computation of emergent semantics for blending media into creative compositions is based on the idea that meaning is endowed upon the media in the context of other media and through interaction with the user. The interactive composition of digital content in modern production environments remains a challenging problem since much critical semantic information resides implicitly within the media, the relationships between media models, and the aesthetic goals of the creative artist. The composition of heterogeneous media types depends upon the formulation of integrative structures for the discovery and management of semantics. This semantics emerges through the application of generic blending operators and a domain ontology of pre-existing media assets and synthesis models. In this chapter, we will show the generation of emergent semantics from blending networks in the domains of audio generation from synthesis models, automated home video editing, and information mining from multimedia presentations.