|In Argentina, Sebastián received a doctorate in composition from Yale and a licentiate in Musicology from the Universidad Católica Argentina in Buenos Aires. He studied composition privately with Gerardo Gandini and Mariano Etkin, in addition to Piano, Voice and Choral Conducting. His teachers at Yale were Ezra Laderman, Alvin Singleton and Joseph Schwantner in Composition and Marguerite Brooks in Conducting. He has also participated in numerous workshops and courses in Composition, Early Music and Technology in America and Europe. During some of these events he worked with Martin Bresnick, Pedro Memelsdorff and Néstor Zadoff.