My master’s thesis project is about creating music for piano and improvising ensemble based on compositions that set the ground for an open improvisation. I wanted to find out methods of how to write and communicate a piece that gives the performing musician a maximum freedom to interpret their parts and still share the same vision of the piece. In order to get there I tried out different strategies of composing and different instrumentations. I also compare this project to previous ones and examine how the playing with the ensemble in this project affected my own style of playing. The exam concert together with this thesis document the process and outcome of this project.