When the curtain goes up Wednesday and Friday on L’Opera Francais de New York’s production of Claude Debussy’s only opera, “Pelléas et Melisande,” much will seem as it usually does. Golaud, the knight whom hunting has driven too far into a dark forest, will discover a cowering young woman unable to convey much more than sheer terror, and he will attempt to take care of her. Despite her pleas to be left alone, they will go off together and join his father and brother, with results that are conventionally operatic yet full of the tragic sentiments of a new age.

Instead of savoring the deep, somber strings that open the opera, however, the audience will hear a solo piano, playing not the standard orchestral score but a special version the composer devised to play for friends and people who might one day stage his opera. These performances will mark the American premiere of a “Pelléas” few have heard of, let alone heard.

This chamber-version “Pelléas” is the first “version” of one of music’s most allusive yet powerful works. “Pelléas’s” soft, atmospheric sounds and its ambiguous story triumphantly linked opera with the Symbolist movement (Maurice Maeterlinck, author of the play from which Debussy adapted his libretto, was one of its leading figures). And suddenly opera – which at the time of “Pelléas’s” premiere in April 1902 had already begun to suffer from the formal conservatism that continues to make its survival so problematic – seemed the perfect vehicle for the ideas of a new age.

Debussy had considered presenting “Pelléaset Melisande” not in an opera house but at one of the many avantgarde theaters that made turn-of-the-century Paris one of the world’s liveliest theatrical milieus. Eventually, a mainstream company, the Opera-Comique (which a generation earlier had premiered another bold French masterpiece, Bizet’s “Carmen”), did present the opera, seven years after Debussy had begun playing the piano “Pelléas” to invited listeners.

“This is definitely not a ‘piano reduction,'” explained Jean-Philippe Clarac, co-artistic director of L’Opera Francais, who is directing this “Pelléas” with his longtime partner, Olivier Deloeuil. “Piano-vocal scores are written after an opera and its orchestral score are finished. This ‘Pelléas’ is, rather, a sumptuous piece of music, written directly for the piano, by one of the most talented 20th-century piano composers.”

The familiar version of “Pelléas’s” features extraordinarily versatile and subtle orchestration, but Mr. Clarac finds little loss in relying on the piano version. “It’s more intimate and intensely focused on the action,” he told me. “In the piano I can hear the line and the structure of the scene in a way I cannot when I hear ‘Pelléas’ orchestrated. You lose this idea of the mystery the orchestra gives to it, but instead you enter another, more intimate atmosphere.”

More than the orchestration is missing. The interludes between scenes are not in the piano version. (These were composed to keep the orchestra playing while stagehands set the next scene.) The loss of those 20 minutes of music is compensated for by a swifter, terser drama, which in the final version fell to the Paris censors’ scissors.

“We were very surprised to discover three pages in this chamber version of Pelléas,’ which were excised just before the Opera-Comique premiere,” Mr. Clarac said. “In the scene where Golaud and Yniold are spying on Pelléas and Melisande through the window, the text as we have it has Yniold mentioning seeing the couple on Melisande’s bed. The censorship before opening night insisted that this be changed – they couldn’t have a child talking about such things – and so three pages were cut.”

To this day opera houses have not rectified the omission, though the Metropolitan Opera does reinstate another censored moment – a passage concerning sheep being led to the slaughter was considered “anti-Christian,” and the sheep didn’t make it to opening night.

The L’Opera Francais de New York production gives New Yorkers a chance to hear, for the first time locally in a leading role, Patricia Petibon, sometimes called “the Bjork of the parterre,” a brilliant young coloratura soprano who is already a huge star in France. Onstage, Messrs. Deloeuil and Clarac have, with production designer Carol Bailey, set the action in a milieu more Upper East Side than medieval Europe.

Lighting designer Rick Martin has devised pure shafts of light, which seem to scrutinize the characters as they act or do not act (just what really goes on in “Pelléas” is one of the opera’s mysteries). “We were inspired by Strindberg’s concept of intimate theater, because this is a family story, a tragedy of the family,” Mr. Clarac said. “All the characters are onstage for the entire opera, and they are always aware of each other. Pelléas and Melisande are never free – someone is always watching them.”

Pianist Raphael Rochet is the musical director of this production, and it is being overseen by the company’s founder, conductor Yves Abel. Mr. Abel founded L’Opera Francais de New York in 1988, and since then it has brought to the city some of the best, the most obscure, and the most chic French music, from rarely heard opera comique to an evening of songs for Art Deco chanteuse Yvonne Printemps.

Mr. Clarac said the company’s mission is “to be complementary to the big houses – not to compete with the Met or City Opera, but to do the things they can’t in ways they can’t do.” The Metropolitan does a superb “Pelléas”(and it will re-enter their repertory, with an excellent cast, for four performances from January 29 through February 8). The very size and organization of their theater, however, preclude the small-but-powerful effect this chamber “Pelléas” promises to deliver.

“Pelléas et Melisande” will be performed January 19 and 21 at 7:30 p.m. at Florence Gould Hall (55 E. 59th Street, between Park and Madison Avenues, 212-307-4100). The Metropolitan Opera’s production will be performed January 29 and February 2, 5 & 8 (Lincoln Center, 212-362-6000).