This chapter discusses Boulez’s formal and informal music education, beginning with his early musical training and his formal studies in Lyon and Paris. In Paris, the importance of his informal education emerges, including his relationships with important mentors. His development as a conductor and lecturer on music is also considered. Although many would consider these professional activities, Boulez’s emergence as a writer, lecturer and conductor was accomplished during a period of extensive experimentation in composition. He reflected, in retrospect, on his mentors and related ‘apprenticeships’ and how they shaped his thinking as a musician. While Boulez was a lifelong autodidact, the discussion closes at the end of his formative period around 1960.