Zedda studied in his native Milan with Antonino Votto and Carlo Maria Giulini, and made his debut there as conductor in 1956, with Il barbiere di Siviglia. He was quickly invited to conduct at most of the opera houses of Italy and began an international career, appearing in Bordeaux, Paris, Vienna, Berlin, London, New York, etc. He was for a time musical director of the Festival della Valle d'Itria in Martina Franca and currently of the Pesaro Festival.
As a musicologist, he is responsible for the revision of numerous works by Vivaldi, Handel, Donizetti, Bellini, Verdi, but most notably Rossini. He is, with Philip Gossett, responsible for the complete critical edition of the operas by Rossini and is a committee member of the Rossini Foundation in Pesaro, Italy. He is also renowned for his research on vocal ornamentation and his aim at authentic performing style.
- Rossini - Tancredi - Ewa Podles, Sumi Jo, Stanford Olsen, Pietro Spagnoli, Anna Maria di Micco, Lucrezia Lendi, Capella Brugensis, Collegium Instrumentale Brugense (Naxos, 1994)
- Bellini - Beatrice di Tenda - Mariana Nicolesco, Stefania Toczyska, Vincenzo La Scola, Piero Cappuccilli, Prague Philarmonic Choir, Monte Carlo Orchestra (Sony, 1986)
- Roland Mancini & Jean-Jacques Rouveroux, Le guide de l'opéra, Fayard, 1986.