Live multimedia performance demands elaborate interactive media-processing systems. The task of these systems is to serve as expressive instruments that support the artist during composition and performance. In order to deal with the rapidly growing amount and complexity of digital content, we propose the application of computer-assisted content editing techniques. Specifically, we present a software component that addresses the artistic workflow by organising the design space of an art work, and providing means of navigation therein. In addition, we present a framework that employs audio and video analysis methods for automatic non-linear video editing. Together, these techniques effectively help the artist to focus on live composition and performance flow instead of getting lost in an unmanageable parameter space.