This chapter provides an overview of the proposal developed in the book. Improvisation is described as a typical human phenomenon present in everyday life and society, a fundamental feature of our existence, and an integral aspect of our daily routine. A brief theoretical review and historical aspects of Musical Improvisation are presented. To conclude the theoretical review, the chapter presents some authors into dialogue to demonstrate that, in its established (classical) conception, musical improvisation is directly linked to creation at the moment that a musical performance takes place. Based on the work of Costa (2013, 2018), the chapter will discuss free improvisation performance as a democratic and non-hierarchical playing field. This possibility of creating without pre-established limits makes the free improvisation creation process unpredictable and dynamic. Due to these characteristics, this practice is a fertile ground for psychological studies on human development and creative processes. The chapter explains why the proposal developed in this book adopts a theoretical-integrative and multidisciplinary perspective between Musical Improvisation and Cultural Psychology. Finally, the methodological aspects adopted during the research and the book chapters are presented.