 A decisive turning point for Monod occurred in 1944 at the age of 17, when he took private lessons in composition and theory for five years, subsequently remaining a lifelong supporter and president of an association promoting the music of the French composer and conductor René Leibowitz, a Webern disciple and émigré from Warsaw, Poland (rumor has it that during the German occupation of France, which lasted until December 1944, the young Monod surreptitiously brought food to Leibowitz, a member of the French Resistance).Leibowitz, who was an outsider among the French musical establishment, and a major catalyst in the promotion of Schoenberg's music and in the subsequent development of serial music in Paris after WW II, became Monod's principal teacher and mentor within a circle of devoted pupils, including , Antoine Duhamel, Pierre Chan, Michel Philippot, Serge Nigg, André Casanova, Claude Helffer, and for a brief period, Pierre Boulez.Monod's debut (1949) as a pianist took place in Paris at a concert organized by Leibowitz for Schoenberg's 75th birthday.