Through the adoption of Mikhail Bakhtins terms, this book presents a new creative theory called Musical Responsiveness. The theory proposes that responsiveness in improvisation is an open-ended, continual process, and that it involves not just creating meaningfulness and harmony, but also engaging laughter, struggle, dispute, and misunderstanding. To become musically responsive is a process of becoming answerable to the client; and in doing so, the therapist undertakes ethical challenges and tensions. Although without immediate implications for what to do, this book offers new insights and fresh perspectives on the use of improvisation in the practice of music therapy.