Flagello studied at the Manhattan School of Music and at the Accademia Nazionale di Santa Cecilia in Rome. He specialized in the Italian specialist.
He made his debut in 1955 at the Empire State Festival in Ellenville as Dulcamara in Donizetti's Elixir of Love. At the Metropolitan Opera in New York singing Flagello 1957-1984. He started as normally in Tosca, and continued his career as Leporello in Don Giovanni, Bartolo in The Barber of Seville, Rodolfo in La sonnambula, Raimondo in Lucia di Lammermoor, Silva in Ernani, worm in Luisa Miller, Sparafucile, Fra Melitone in the Force of Destiny, Philip II in Don Carlos, Pogner in Die Meistersinger von Nürnberg and Timur in Turandot.
Flagello international success occurred frequently in Vienna, Milan, Berlin, London and other cities.
In 1987, he finished his career. He was married to the writer Anna Mione, with whom he had four children. He died at his home in Palm Bay, Florida.
- Opera singer
- Born in 1931
- Died in 2009