Born in Assisi, Lazzari began his career performing with the Vitale Operetta Company from 1908 to 1911; making his professional debut as L'Incognito in Franz von Suppé's Boccaccio.
[1] He was committed to the Teatro Colón in Buenos Aires for the 1914–1915 season, and appeared at the Municipal Theatre of Santiago in 1915 as Aldobrandino dei Rangoni in Mascagni's Parisina.
[3][4] In 1916 Lazzari performed the role of Archibaldo in L'amore dei tre re at the Palacio de Bellas Artes in Mexico City and gave his first appearance in North America in Saint Louis.
[3] In 1917 he was committed to the Boston Opera House, and made his New York City debut performing Colline in Giacomo Puccini's La bohème with Maggie Teyte as Mimi and Luca Botta as Rodolfo at Columbia University to an audience of 2,000 people.
[17] Other roles he sang at the Met included Alvise in La Gioconda, Archibaldo, Colline, Count Rodolfo, Don Basilio, Dr. Bartolo in Mozart's The Marriage of Figaro, Ferrando in Verdi's Il trovatore, Leporello, Lothario in Mignon by Ambroise Thomas, Oroveso in Bellini's Norma, the Prefect in Linda di Chamounix, Raimondo Bidebent, Ramfis, Samuel in Verdi's Un ballo in maschera, Simone in Puccini's Gianni Schicchi, Sparafucile, Talpa in Puccini's Il tabarro, and Varlaam in Mussorgsky's Boris Godunov.
[19] Lazzari appeared annually at the Salzburg Festival from 1934 to 1939; portraying such roles as Bartolo in The Barber of Seville, Leporello in Don Giovanni, and Pistola in Falstaff.