She sang mainly at the New York Metropolitan Opera and is generally considered to have been one of the greatest sopranos of the 20th century

She was born Rosa Ponzillo on January 22, 1897, in Meriden, Connecticut, the youngest of three children. The family lived on the city's west side in a neighbourhood chiefly populated by immigrants from the south of Italy, first at the corner of Lewis Avenue and Bartlett Street, then on Foster Street, where Ponselle was born, moving when she was three to Springdale Avenue. Her parents were Italian immigrants from Caiazzo, near Caserta. Ponselle had an exceptionally mature voice at an early age and, at least in her early years, sang on natural endowment with little, if any, vocal training. Instead, her early prowess as a piano student (which was cultivated by a local music teacher, Anna Ryan, the organist of a nearby Catholic church), seemed to incline Rosa to instrumental rather than vocal music. But with the influence and example of her older sister, Carmela, who was then pursuing a career as a cabaret singer, Rosa began to augment her engagements as a silent-movie accompanist in and around Meriden by singing popular ballads to her audiences while the projectionist changed film reels. By 1914, her reputation as a singer led to a long-term engagement at the San Carlino theater, one of the largest movie houses in New Haven, near the Yale campus

Vaudeville[edit]

By then, Carmela was already an established singer in vaudeville after her debut in The Girl from Brighton, a 1912 Broadway musical. Three years later, in 1915, Carmela brought Rosa to audition for her vaudeville agent. In spite of being markedly overweight (a stark contrast to the fashion-model physique of her older sister), Rosa impressed with her voice, and she was hired to perform with Carmela as a "sister act". Between 1915 and 1918, the Ponzillo Sisters (also known as "Those Tailored Italian Girls") became a headlining act on the Keith Vaudeville Circuit, appearing in all the major Keith theaters and earning a substantial income in the process. The sisters' act consisted of traditional ballads, popular Italian songs, and operatic arias and duets.

Metropolitan Opera debut and early operatic career[edit]

Rosa Ponselle made her debut at the Metropolitan Opera on November 15, 1918, just a few days after World War I had ended, as Leonora in Verdi's La forza del destino, opposite Caruso and Giuseppe De Luca. It was her first performance on any opera stage.In addition to Leonora, Ponselle's roles in the 1918/19 season included Santuzza in Cavalleria rusticana, Rezia in Weber's Oberon, and Carmelita in the (unsuccessful) world premiere of Joseph Carl Breil's The Legend.

In the following Met seasons, Ponselle's roles included the lead soprano roles in La Juive (opposite Caruso's Eléazar, his final new role before his death in 1921), William Tell, Ernani, Il trovatore, Aida, La Gioconda, Don Carlos, L'Africaine, L'amore dei tre re, Andrea Chénier, La vestale, and the role that many considered her greatest achievement, Bellini's Norma, in the Met's historic 1927 revival. In addition to her operatic activities, which were centered at the Met, Ponselle had a lucrative concert career. A tour of the West coast included an appearance at the Lobero Theatre in Santa Barbara on March 14, 1927 in the Artist Series of the Community Arts Association's Music Branch, accompanied by pianist Stuart Ross.