This thesis and portfolio of compositions are the result of four years of research conducted through compositional practice and theoretical reflection. This thesis examines in some depth, what the art and craft of composition could be in the context of information age paradigms of communication and interaction. It provides an investigation into compositional approaches fitting to contemporary means of music-making. The focus of this project is composition through real-time, interactive performance systems, this subject is examined within the wider context of network performance, musical interaction and design, live electronics, live scoring, spatial consideration in composition, and new notational practices. This thesis presents the notion of a performance ecosystem, a ground from which a work of art can emerge through the act of performance. The performance ecosystem is conceived of as a self-generating environment that engages a process of genetic replication to expand the system in scope and complexity. Within these performance ecosystems, actions and interactions are generative, and the work is negotiated in real-time between multiple, independent yet interdependent actors. The product of this activity is not only the ensuing sounds, movements, and images that are created, but also the system, with all of its infrastructure and possibilities, and the performance act, as a combination of negotiations and explorations, through which each performer and experiencer partakes in a literal journey through the work. I believe that the performance ecosystem presents a satisfying framework for artistic creation in the context of contemporary constructs of creativity, thought, relationship and being and the way they are represented, experienced and engendered.