Rufus Wainwright's "Prima Donna" took an unusual path to its United States premiere, switching companies and sopranos.

Commissioned by the Metropolitan Opera and then dropped four years ago in a language dispute, "Prima Donna" opened Sunday in a performance by the beleaguered New York City Opera at the Brooklyn Academy of Music _ a run threatened by labor strife until a contract was reached with unions last month.

At times haunting, at times filled with shimmering lyrical passages and at times maddeningly slow, the first opera by the 38-year-old singer-songwriter showed promise and was greeted with an enthusiastic response. It simultaneously delights and disappoints, a melodic throwback to the era when Puccini and Strauss were composing, with arias and duets and quartets. But the pacing is uneven, coming nearly to a standstill in the first act.

Set in Paris on Bastille Day in 1970, the opera is about fictional soprano Regine Saint Laurent, who retired suddenly six years earlier at the height of her profession. Much like the Marschallin in Strauss' "Der Rosenkavalier," she must face her own aging, a turn inward set off by the visit of Andre Le Tourner, a journalist who is as much an admirer as he is a reporter.

She is surrounded by momentos of her last triumph in "Alienor d'Aquitaine," and she intends to return to the stage in that role. But Le Tourner forces her to confront the jarring events in her final performance that caused her to quit singing. Introspection convinces her that not only is her voice broken, but her spirit is too.

Originally part of a joint program of the Met and Lincoln Center Theater to develop new works, "Prima Donna" was dropped by those companies because Wainwright and Bernadette Colomine composed the libretto in French, not English. It premiered at the Manchester International Festival in July 2009, then traveled to North America for Toronto's Luminato festival the following June.

The son of folk singers Loudon Wainwright III and Kate McGarrigle, Wainwright is a self-described opera junkie, and the composition is an homage that shows influences from several 19th- and 20th-century composers such as Puccini, Strauss and Britten. The harp and timpani are used in many pretty passages. The most effective number, an aria by the maid Marie entitled "Picardie," is at the start of the second act when she sings of the differences between Paris and her home. It is more concise than any of the music given to Regine.

In a role reminiscent of Norma Desmond in "Sunset Boulevard," soprano Melody Moore took over as Regine from Janis Kelly, who sang in the premiere and was announced for this run in December 2010.

Somewhat restrained and not nearly as mannered as some real-life divas, Moore needed to be more over the top in her affectations to befit a faded star of stature. Wainwright gave her soaring vocal lines, and she filled them with color, although some turned strident toward the top. She gets two arias, "Quand j'etais jeune etudiant (When I was a young student)" and "Feux d'Artifice (Fireworks)," which is sung while looking out at the Bastille Day celebration and seems anticlimactic.

Taylor Stayton gave a bright tenor to Andre, who makes no effort to hide his fawning over Regine. Coloratura Kathryn Guthrie Demos was a perky Marie, who comes off as the one sane person in the apartment, and her voice lent a spark that cut through the sometimes syrupy score. Randal Turner, as the officious manservant Phillipe, provided a sturdy baritone.

Conductor Jayce Orgren led the City Opera orchestra, which produced a luminous sound. Antony McDonald's set was a huge room in a Paris apartment that had seen its better days _ Regine has been forced to sell her Picasso. Tim Albery directed in place of Daniel Kramer, who staged the original. Thomas C. Hase's lighting in the opening and closing scenes was memorable.

Wainwright, wearing a tailcoat with shiny silver chain and knit black hat, received a loud ovation during the curtain calls from the filled house, many of whom bought $25 tickets that had been subsidized by a foundation. At its world premiere, he had dressed as Verdi.

Those attending may want to study up: The program devotes all of 56 words to describing the opera.

There are additional performances at BAM's Howard Gilman Opera House on Tuesday, Thursday and Saturday.