He was particularly associated with La Scala in Milan, the San Carlo in Naples, and the Rome Opera, where he was artistic director from 1945 to 1962. He also made guest appearances at the Paris Opéra and the Royal Opera House in London.
He conducted several creations of Italian contemporary works notably by composers such as Umberto Giordano and Franco Alfano, but was especially admired as a rock-solid maestro of the old school in the standard Italian repertory. Considered one of great Verdi conductors of his generation, he left notable recordings of Simon Boccanegra and Don Carlos, both with Tito Gobbi and Boris Christoff, as well as La traviata with Maria Callas.
- Le guide de l'opéra, R.Mancini & J.J.Rouvereux, (Fayard, 1986) ISBN 2-213-01563-5