This thesis investigates approaches to composition and performance in a jazz context where large ensembles are encouraged to spontaneously create arrangements of the composed material in real-time. Case studies explore examples of compositions and performances across the chronology of jazz history and beyond, specifically Joe “King” Oliver’s Canal Street Blues , Duke Ellington’s Concerto for Cootie , Earle Brown’s December 1952 , Charles Mingus’s The Black Saint and the Sinner Lady , John Zorn’s Cobra and Lawrence “Butch” Morris’s practice of Conduction and the commonality of a performer-centric approach across all compositions is identified. It is demonstrated that Butch Morris’s Conduction can be viewed as a compendium of signs and gestures that allows many of the techniques of performer-centric compositions developed throughout the twentieth century to be generated spontaneously in performance. The thesis concludes with a reflective approach, where compositions influenced by these case studies are presented and discussed as well as a final extended work that synthesises the findings of the project.