In music education contexts, improvisation is currently a rapidly evolving field across musical genres. Writing on improvisation has so far been largely concerned with justifying improvisation’s place in music education, by making visible its many practices in a broad range of music cultures and by highlighting its beneficial and positive dimensions. However, there are challenges and unexploited potentials within improvisation pedagogy, such as deficiency in teacher qualification, or tensions between contrasting pedagogical purposes, values, and ideologies. In this chapter, the authors problematise improvisation pedagogy and its legitimation, and present the scope of the book as a whole, through posing the questions: Who defines the artistic expectations of improvisation activities, who are the gatekeepers? How much freedom is involved? Who has creative agency – teacher or students? What professional ethical standards do teachers have? The various chapter contributions all relate to these issues from a wide array of contexts and research disciplines. The overall objective is to broaden the understanding of the potentials and possibilities for improvisation in a variety of music education contexts, and stimulate the development of knowledge and reflection on improvisation in music pedagogy.