This thesis presents a critical examination of the processes of creativity in the performance of Persian classical music. Using current literature, information from musicians, and detailed musical analyses, the thesis endeavours to reach an understanding of what creativity means in the Persian context, and to examine the ways in which creativity takes place and the factors which affect it. A consideration of the nature of human creativity in general is followed by a critique of the concepts and terminology of creativity used within (ethno)musicology. Several areas are subsequently explored for their potential contribution to an understanding of creative musical processes. There is a consideration of possible parallels between musical and linguistic creativity, as well as an exploration of theories about the psycho-physiological determinants of musical creativity. With specific reference to Persian classical music, various aspects of the basic canonic repertoire, the radif, are examined, and this is followed by a discussion of the processes by which the radif is learnt, this being a crucial stage in laying the foundations of musical creativity. There is also a consideration of the concepts of creativity in this musical tradition, as well as changes to such concepts in recent years. The musical analyses focus on a number of performances and versions of the radif, primarily from dastgah Segah. There is an examination of the sectional organisation of both performances and radifs, as well as of compositional procedures, typical melodic patterns, and including specific focus on the ways in which material from the radif is treated in performance. The aim is to comprehend how it is that musicians use the knowledge acquired during training to present unique expressions of the musical tradition at every performance occasion. The thesis seeks to contribute to a greater understanding of generative musical processes and ultimately, towards a better understanding of the nature of human creativity.