After the Santa Fe Opera's house lights went down following the national anthem on Friday evening, conductor Frédéric Chaslin raised his baton and drew gentle, minor-key chords from the orchestra. Misty yet carrying, they were succeeded by a sadly soaring melody that seemed to be filled with regrets for time past and love ended.

As the music flowed on, tenor Saimir Pirgu walked onstage and onto the gray, stark set — a series of blocks, platforms and connecting stairs of varying heights that might be anything from a cubist cemetery to the landscape of a fevered mind. He walked downstage, then turned to watch a procession of soberly clothed people pacing upstage behind a coffin borne high. They moved slowly and deliberately, sheltered by rain-speckled umbrellas, as they followed the unseen burden to its final resting place. The stage back wall, open to lowering clouds and a sullen sunset, seemed to extend the picture into infinity.

The grave folk departed to the grave site, the stage cleared, the prelude faded away — and suddenly soprano Natalie Dessay was there, perched high on the set and startlingly vivid in a fuchsia dress and lace-up high boots, flaming red hair piled high on her head. She was a bacchante embodiment of Violetta, the "woman gone astray" of the opera's title.

She swung her arms above her head, stretched, and then literally screamed out what sounded like wild joy and barely bridled lust. The lights blazed up, the stage suddenly swarmed with partying people, the orchestra exploded into wild hilarity, and Pirgu stepped into the scene as Alfredo, Violetta's yearning suitor. SFO's new production of Verdi's La Traviata, and one certainly unlike any the company has mounted before, was on its startling and glorious way.

Dessay has waited some years to sing Violetta, and it's our luck she decided to perform it here first. The role is famously difficult vocally, so taking it on outside the Chicago-New York-London-Paris circuit was perhaps a factor. On the other hand, SFO can offer the world-famous soprano the concentrated rehearsal time she prefers for every project, plus the kind of intelligent colleagues she demands.

Dessay was physically amazing in this complex part as she leapt, hopped, ran, danced and was acrobatically carried about. Every motion had meaning, every look had intent behind it. And the singing? I've heard Violettas with bigger or more velvety voices, but none with Dessay's sense of vocal stagecraft, textual authority, and intrinsic ability to enchant. This was not a soprano singing Violetta: It was one woman embodying another. The character was present before us, full of love and sorrow, rather than being a prettily sung pretense.

Not that there wasn't plenty of compelling singing. The fleet coloratura flourishes in the "Sempre libera" scene were as vital as Violetta's anguished, lyric sorrow later. Her dying wisps of sound in the last act seemed like they already came from another world. Even a few tiny breaks in the voice here and there, especially on soft high notes, were deftly incorporated into the character and the moment. It was an interpretation to remember and cherish.

Dessay had a seductive lover in Pirgu. His dark good looks fit Alfredo's romantic character, and his agreeable, light tenor proved capable of both ardor and delicacy. He was nicely accomplished and vocally graceful in the first and second acts; but in the confrontation scene in the third act, and in the final duet with the dying Violetta in the fourth, he reached even higher levels of passion and power.

Making his role debut as Germont, Alfredo's father, Laurent Naouri offered a stern presence wrapped up in moral rectitude. He sang authoritatively with a tightly coiled, sometimes burry baritone sound. His buttoned-up garb and lean height made him seem like a pondering judge, so it was interesting to hear and see a softer side as he begged Alfredo to return home. The excellent tenor Keith Jameson and the bronze-voiced baritone Wayne Tigges brought vocal distinction and first-rate acting to the small but vital roles of Gastone and Douphol, and the other smaller roles were more than capably taken by SFO apprentice singers.

Director and costume designer Laurent Pelly, who has only done comedy at SFO before, took a number of big dramatic risks in handling the opera, and most of them paid off. As you might gather from the above description, this Traviata isn't about sumptuous settings filled with sedate courtesans and their benevolent sugar daddies — though the costumes are, in fact, gorgeous. The crowd scenes on Chantal Thomas' sets are downright debauched, at least for Santa Fe Opera and especially when so enterprisingly lit by Duane Schuler. The second act at Violetta's country home takes place outside on grassy banks, and she wears a boy's trousers and shirt — more than slightly shocking Germont père.

The Act III party scene is endlessly delightful, for Pelly came up with a very effective solution of how to handle the big choral set pieces without crowding the stage with dancers and supernumeraries. His nearly seamless transition from the party to the dying Violetta's sickroom was a hushed, melting, coup de théâtre.

I've never heard the SFO orchestra — which has many new members this season — and chorus sound better than they did under Chaslin's guidance. Not that he added anything to the score: He simply pointed out what was there, and demanded that it be properly performed. Points often bypassed by other conductors were suddenly present, including abrupt dynamic contrasts that defined important moments, carefully painted inner voices, and excellent balance both within the orchestra and between pit and stage. Violetta herself may be wayward, but Chaslin's leadership was rock solid and sheathed with gold.

La Traviata repeats at 9 p.m. Wednesday and runs through Aug. 29. Information: 986-5900.

Contact Craig Smith at 986-3038 or csmith@sfnewmexican.com.