At present, historically-informed performance (HIP) functions simultaneously as an established musical tradition and as a method for artistic inquiry and renewal. HIP’s capacity to effect change within artistic practice is, however, constrained by its own doxa. This study of Mark Edwards therefore asks the question: what kinds of new practices might have once been, and might still become possible without the influence of the work-concept? Using the keyboard music of Jacques Champion de Chambonnières as its central case study, this dissertation proposes understanding a piece’s fluid range of identities using the concept of mouvance, conceived as a kind of variance that arises within performances and is acknowledged by cultural participants (audiences and performers). Moreover, this study attempts to re-create this practice of mouvance by also re-creating the improvisational practice upon which mouvance relied. To that end, it adapts and extends existing research on historical improvisation (particularly studies of partimento) using techniques from computational musicology. It puts forward an “inductive” approach to style re-creation and improvisation pedagogy in which techniques and procedures are extrapolated from highly specific repertoires. Through mouvance, this study thus offers a new and historically-informed approach for applying the insight gained through improvisational practice to the creative performance of historical repertoires.