The premiere of the Metropolitan Opera’s new production of Gounod’s “Romeo et Juliette” a week ago was a palatable affair even without its star soprano, Natalie Dessay, who was laid low by a cold. Maureen O’Flynn gave a perfectly creditable performance in her stead, but there is no denying the artistic boost Ms. Dessay gave the enterprise when she joined the cast at the second performance on Thursday evening.

The Met has had many Juliets over the years, very few of them French. Madame Desay, however, suffused this performance with Gallic charm. The voice sounded as lovely as ever – clear, limpid, pure – but it was the subtlety of Ms. Dessay’s vocal inflections and her care with words that made her performance especially memorable.

She also gave Juliet a wide emotional range. At first, she made her seem delightfully naive by singing coloratura passages of the famous waltz as if they were emotional gushes over Romeo. But her mood turned intensely serious for the Act IV duet – the lovers’ final moment together before Romeo’s banishment – and the piece rightly emerged as the crux of the opera. Ms. Dessay’s compelling singing and that of her sweet-voiced Romeo, Ramon Vargas, made me grateful that Bertrand de Billy, the production’s excellent conductor, has restored a substantial traditional cut in this duet. Later, Ms. Dessay alternated tellingly between fortitude and fragility in Juliet’s affecting potion aria.

At Thursday’s performance, the intermission was extended by a delay, which was attributed in an announcement to technical difficulties. When the curtain went up, the bed from which the lovers sing their duet rested firmly on a platform, whereas at the premiere it had floated several feet above, making me fear for the singers’ safety. According to a Met spokesman, there were problems on Thursday in stabilizing the bed. Whether the change is permanent remains to be seen. The singers moved with greater freedom when the bed was on terra firma. On the other hand, the sight of the floating bed, though modest as these things go, was the production’s most striking visual effect.

“Romeo et Juliette” will be performed again tonight, November 25 & 28,December 1, February 21 & 25, and March 1, 4 & 9 at the Metropolitan Opera House (Lincoln Center, 212-362-6000).