For the launch, in a Baroque church at the edge of the Roman Forum, of Cecilia Bartoli's latest CD, Opera Probita ("Banned Opera"), the charismatic Italian mezzo-soprano has been labelled "la dolce diva" by her record company. The singer is resplendent in a specially commissioned Vivienne Westwood gown of pewter-hued silk, inspired by the sensuous sculptures of Bernini. As she sings Alessandro Scarlatti's "L'alta Roma, reina del mondo" ("Noble Rome, queen of the world"), two massive doors behind the platform swing open into the warm night, revealing a floodlit landscape of pillars more than 2,000 years old. For an hour, accompanied by Les Musiciens du Louvre under the direction of the French conductor Marc Minkowski, Bartoli treats her guests to a programme of arias by Handel, Caldara and Scarlatti.
Opera Probita is probably Bartoli's most original and exciting recording to date. It is, in effect, a multi-layered concept album, mingling the music of Baroque Rome with some deliciously sophisticated ambiguity. It's a complex cocktail of forbidden fruit, in which sensual music is masked as sacred, matched in presentation by tongue-in-cheek imagery inspired by Fellini's La Dolce Vita. The album has gone straight to No 1 in the US classical charts and is Recording of the Month in Gramophone. Bartoli is bringing its repertoire to London, with a performance at the Barbican on 7 December.
The evening in Rome proves unforgettable. Opera is in Bartoli's blood. Born in the city, she was virtually raised in the Teatro dell'Opera, where her parents both sang in the chorus. "I must have started listening to musicians while I was still in my mother's uterus," Bartoli declares, gazing out over the Forum. "I grew up with the great operas of Verdi and Puccini, in which my parents used to sing. But I then had to take a different repertoire, because I had to follow my voice, my instrument."
Bartoli's warm, supple, honeyed voice carried her first to 19th-century Italian bel canto roles that demand precision, focus and beauty, rather than volume of sound. She has always kept Rossini operas at the heart of her work: earlier this year she thrilled audiences at Covent Garden in Il Turco in Italia, a fabulous production by Moshe Leiser and Patrice Caurier that updated the action to the era of the films of Pasolini and Fellini, complete with an authentic Vespa and a well-timed takeaway pizza. "It was a wonderful experience and the audience enjoyed the production so much that every performance felt like a kind of feast!" Bartoli exclaims.
But while others with a voice as gorgeous as Bartoli's might be expected to dive from stage to stage, you're more likely to find her in a university library, hunting out rare Baroque gems. Her ambitions extend not forwards to Puccini, but backwards to the ground-breaking Renaissance works of Monteverdi. "I would love to sing Monteverdi's L'incoronazione di Poppea," she says, "as well as more Handel operatic roles, like Alcina or Agrippina."
What about every mezzo's ultimate operatic prize: Bizet's Carmen? "Interestingly, the Opéra Comique in Paris, where this opera was first staged, is rather small, with a tiny orchestra pit," Bartoli says, a gleam in her eye. "The first production of Carmen must have been created for this kind of atmosphere, with real intimacy. We're used to seeing Carmen as a big, spectacular show. So a Carmen back to the source, yes. Back to Bizet! Otherwise, no."
Bartoli's journey into the past began when the conductor Daniel Barenboim suggested she should consider singing Mozart roles such as Dorabella in Così fan tutte and Cherubino in Le nozze di Figaro. "He opened me to the universe of Mozart and classicism," Bartoli recounts. Since then, she's also worked extensively with conductors such as Nikolaus Harnoncourt and Christopher Hogwood, accompanied by orchestras of period instruments. She's a tremendous enthusiast for "early music". "I think that we singers have an old instrument," she explains. While musical instruments changed dramatically over the 19th and 20th centuries, the human voice has remained the human voice. She points to the difference in tone between old-style gut strings and modern metal ones on a violin. "We didn't have that kind of development! The voice still sounds more like gut strings."
Opera Probita began with Handel. "He brought me back to Rome," Bartoli enthuses. "What we see in the Forum today is exactly what Handel saw when he arrived here, aged only about 21. Imagine the effect on him, coming from the north of Germany! I'm sure he was totally impressed; there's a sense of astonishment in his music." Her mission was initially to explore the music of the young Handel and his contemporaries in Rome, but soon the heat was on. "We found some incredible music, but also an incredible story: the story of prohibition. This was the era during which opera was banned by the Vatican, because it was considered immoral, especially the stories being portrayed on stage. But some of the cardinals who loved opera began to write their own libretti with sacred, biblical or allegorical themes." These oratorios therefore became a substitute for opera, with music that is distinctly operatic in nature, "full of drama, passion and a real sense of theatre".
A further prohibition was that women were forbidden to perform on stage. Hence the rise of the "castrati", male sopranos whose vocal timbre was famously achieved by a painful operation at puberty. The greatest castrati were revered as performers and many of the astonishingly athletic arias in Bartoli's Opera Probita were composed for them. Bartoli is effectively singing arias for male singers portraying female characters. "Technically, it's very demanding," she adds. "You never know if you can manage, as a woman, to sing this music which is so virtuosic. Sometimes you have to sustain a long line to the end of a phrase, but the phrases were extremely long to suit men's greater oxygen capacity."
Where does La Dolce Vita come into it? "When it was released in the Sixties, it was considered immoral and anti-Catholic, so it was a little like what happened at the beginning of the 18th century with theatre and opera. Also, there's a big scene with Anita Ekberg having a good time in the Trevi Fountain, and another where she walks through the 17th-century streets of Trastevere with a little cat. These are very Baroque visions! So we have the parallel of prohibition, we have the Baroque vision more in the modern direction but keeping the Baroque element, and Ekberg herself is a Baroque figure - a voluptuous, sensual woman like the sculptures of Bernini."
And the pictures in Bartoli's album, portraying her ecstatic and abandoned against surging Roman fountains, weren't snapped in the Fontana di Trevi itself, were they? "Ah," Bartoli jokes, "if the temperature is still 28 degrees in the afternoon and there's no police around..." The image is striking. Is this the sensual world of Bernini's fountain, or a symbolic flood of divine grace? Hear Bartoli sing and they become one and the same.
Cecilia Bartoli performs at the Barbican, London SE1 (020-7638 8891) on 7 December; 'Opera Probita' is out now on DeccaReuse content