The son of an architect, Chaslin studied at the Conservatoire de Paris (Conservatoire national supérieur de musique et de danse de Paris), where he won first prizes in harmony, counterpoint, fugue, piano accompaniment, vocal direction, and orchestration. He later studied at the Mozarteum University of Salzburg, where his mentors included Paul von Schilawsky. Personal quote: "I'm happy being busy, as long as I'm busy being happy".