At age three, Agostini moved with his family to Montreal. His father, Giuseppe Agostini, was a composer and conductor and it is from him that he had his inititial musical training beginning at age 5. He later pursued further studies in harmony and composition with Louis Michiels and Henri Miro and in cello with Peter Van der Meerschen.
At 16, Agostini was playing with the Montreal Philharmonic Orchestra as a cellist and was a part-time band player in a nightclub band playing saxophone and clarinet. It is at 18 years of age that he began his professional music career working first with Canadian Broadcasting Corporation radio and later with television. Agostini began a long career with the Canadian Broadcasting Corporation in Toronto from 1943, beginning with radio work, and subsequently the broadcaster's US-based television programs through the 1950s. He partook in the production of Front Page Challenge, The Tommy Ambrose Show and The World of Music.
- Conductor led first CBC program at 18, The Globe and Mail, The Arts, Saturday, 17 February 1996. C2. accessed on 18 October 2006.