Notoriously difficult to cast, Bellini's Norma would scarcely be worth mounting at all without a soprano who could manage the title role's tremendous artistic and technical demands. San Francisco Opera elected to open its 92nd season with Norma because they had just such a singer in soprano Sondra Radvanovsky. Surrounding her with a new production by Kevin Newbury, a superb Adalgisa in young mezzo-soprano Jamie Barton, and the company's music director Nicola Luisotti in the pit, the momentous opening night was a fitting inaugural for what is clearly the company's most ambitious season in years. While the evening, as a whole, may not have met the sky-high expectations, the artist at the center of the enterprise exceeded them.

Last fall, Radvanovsky's triumph as Norma at the Metropolitan Opera arguably established her in the legendary company of Maria Callas, Joan Sutherland, Shirley Verrett, and Rita Hunter. My companion, who heard them all, remarked at the time, "She [Radvanovsky] is not as interesting on stage as Callas, but no one has ever sung it so beautifully". While many of us could only compare her portrayal with a less distinguished roster of aspirants from the 1990s and 2000s, it was clear that something extraordinary had happened that night.

The only mitigating factor was the unrealized hope that the Adalgisa from the alternate cast, Jamie Barton, who was also causing quite a stir, would get paired with Radvanovsky. It did not happen. Any lingering "what ifs" were laid to rest at the San Francisco Opera opener. The "dream team" pairing almost didn't happen this time either; until the withdrawal of another artist last week, Barton, the recent winner of the prestigious BBC Cardiff Singer of the World Competition, was not even scheduled to sing in San Francisco. We were lucky to have her. Barton's mezzo soprano exhibited a brightness and fluid flexibility throughout its range, achieving a range of colors without ever turning dusky. She more than held her own in her two big duets with Radvanovsky, especially the famous "Mira, o Norma".

Yet it is the singer in the title role who must bear the burden of creating a great performance of Norma and Radvanovsky was in command from the moment she walked onstage. Her "Casta Diva" was sung with reverent care for the beloved melody, but her interpretation transcended respect for tradition, it was personal, heartfelt, and confident. Radvanovsky's radiant tone and breathtaking control were a privilege to experience live. Though it felt like "ladies night" - even soprano Jacqueline Piccolino stood out in the small role of Clotilde – there were also some bright moments for the men, principally the Oroveso of Christian Van Horn. Last heard here as the four villains in Les Contes d'Hoffmann, Van Horn roared appropriately as the zealous priest who pleads with Norma to lead her people in revolt against the Romans. Tenor Marco Berti was equally forceful as the Roman Pollione, though his contribution did not match the bel canto standards of Radvanovsky and Barton, his partners in the story's love triangle.

Newbury's new staging, a co-production with Canadian Opera Company, Gran Teatre del Liceu and Lyric Opera of Chicago, is hopefully a work in progress. The director confined the action to a massive wooden fortress designed by David Korins; its single portal to the outside world conveying the cultural and physical isolation of the druids. While there were some arresting stage pictures, the crowd movements and dramatic scenes did not cohere with Newbury's apparent taste for static visuals. Crucial moments were interrupted by costumed stage hands moving props into place so that a fresh tableau might accompany the beginning of the next scene. Perhaps Newbury intended to pre-empt applause after each number and keep the action moving, but confusion about when or whether to clap was more often the result. Unfortunately, his strategy paired sensational singing with scene changes business on too many occasions.

In spite of the outstanding soloists on hand, a shortage of opening night fervor seemed to hinder the orchestra and chorus. Admittedly, opening the program with a sober profusion of "thank you" greetings by the General Director, Board President, and Chairman (delivered from behind a lectern on the stage) did not exactly convey the lobby energy into the auditorium, but Luisotti's relaxed tempi also seemed to feed a brooding inertia. The plodding, matter of factness also infected the chorus and their calls for "Guerra, guerra" in Act II were unconvincing. On the strength of its leading ladies, this Norma has remarkable potential to coalesce as the run progresses.