Giulietta Simionato

If she was not as widely known beyond the opera house as Maria Callas or Renata Tebaldi, both of whom she sang with on many occasions, Giulietta Simionato could nevertheless hold her own on stage – and was no less forceful in the offstage machinations that have long dominated the world of Italian opera.

Attractive, vivacious and full of humour, she was hailed as the natural successor to Conchita Supervia, who a generation earlier had mastered all Rossini's operatic roles; yet she was no less at home in the tragic roles of Verdi. Indeed, Toscanini once remarked of her: "How divinely beautiful she makes her death."

Giulietta Simionato worked with many of the great artists of the 20th century, including the soprano Mafalda Favero ("There was an animal sensuality about her that was spellbinding") and the bass Cesare Siepi ("His voice was pure gold"); there were also appearances with the conductor Herbert von Karajan and the tenor Jon Vickers, who described her as having the "most supreme seamless voice from the bottom to the top I have ever heard".

Giulia Simionato was born at Forli, near Bologna, on May 12 1910, the daughter of a prison governor. Much of her childhood was spent at her mother's family home in Sardinia, although she was educated at a convent at Rovigo, near Venice. Her musical talent was soon spotted by her teachers, but her mother, who died when she was 15, refused to countenance singing lessons.

However, an amateur opportunity at the Teatro Sociale in Rovigo in 1927 was a triumph: "La Simionato has a beautifully flexible voice, a quick intelligence," noted a critic. Her father relented over the lessons and in 1933, in Florence, she saw off 384 competitors to win a bel canto vocal competition at the Maggio Musicale Fiorentino – among the jurors was the conductor Tullio Serafin.

In 1936 Giulietta Simionato was given a contract at La Scala, Milan, but this proved to be for little more than a wearying succession of small or understudy roles. Elsewhere, while minor roles at provincial opera houses flooded in, major roles evaded her – often, she felt, for reasons of jealousy on the part of others. But there were occasional moments of glory, such as in 1940 in Pietro Mascagni's Cavalleria rusticana, conducted by the composer, in which she was the youngest member of the cast and her "son" was 20 years older than she; and at the Bologna Music Festival of 1945, when she reputedly received 35 curtain calls.

Her real break came in 1947 in the title role in Ambroise Thomas's Mignon at Genoa, a role she repeated with triumphant results a few months later at La Scala. From then on there was no looking back. She was heard in Britain as Cherubino that year in Glyndebourne Opera's production of The Marriage of Figaro at the first Edinburgh Festival; and in 1953 she stepped in for an indisposed Fedora Barbieri at Covent Garden with Callas in Aida conducted by Sir John Barbirolli. Her New York debut was delayed because of laryngitis and she made her first US appearance in Chicago in 1954.

The demands of her career were high. She described how on one occasion she sang on 13 consecutive nights, commuting between Milan (Norma) and Rome (The Barber of Seville): "At the end of each performance I rushed to the station, where the guard was already waiting to give the signal for departure. I would take off my make-up in the train."

Giulietta Simionato adored the trappings of success; indeed, one profile noted how she collected furs "as other women collect antiques". Meanwhile, she spoke bitterly of the "enemies" who she felt had held her back in her early years. She was, she admitted, by nature a jealous person, and liked nothing more than gossiping about the infidelities, real and supposed, of her co-stars in Milan.

After an early first marriage to a violinist, she married secondly, in 1965, Professor Cesare Frugoni, who had been surgeon to Mussolini; she retired from the stage at about the same time – while still in excellent voice – to be with him. After his death in 1978 she married an old friend, who died in 1996.