CECILIA BARTOLI, MEZZO-SOPRANO. Music by Vivaldi. Luca Pianca, lute. Il Giardino Armonico, Giovanni Antonini, conductor and flautino. Attended Tuesday night. Carnegie Hall.

CAN THE WORLD'S most famous baroque composer be underrated? Absolutely, which was the point behind Cecilia Bartoli's concert at Carnegie Hall on Tuesday. Antonio Vivaldi, who was considered a dangerous character in his day (the early 18th Century), has settled into pampered posterity. His craftily bizarre, mercurial music has become a form of corporate decoration. He has been popularized into oblivion.

To rescue Vivaldi from his pastel ubiquity, the archaeologically minded mezzo brought to Carnegie Hall an anthology of excerpts from his hitherto utterly forgotten operas. She was abetted by the Milan- based ensemble Il Giardino Armonico, with whom she breathes in synch. Theirs is an agitated, blistering baroque, with none of the prettified trills and greeting-card flourishes of standard shopping- mall Vivaldi.

Here, accents burst from the beat, dissonances gnash, violins dash into a scrimmage of sixteenth-notes. Everything is precise and delicately controlled, but with an undertow of violence. Tuesday's performances captured the unpredictable, natural ferocity of this music, which comes, after all, from Venice, a city separated from nature by the most fragile meniscus. But not all was disquiet: In the sweetly vernal "Zeffiretti che sussurate," the singer and a mimicking violinist engaged in a call-and-response, like the dialogue of coquettish birds or amorous breezes.

It's hard to overstate how fresh this music sounded, and how obscure it has been. The standard reference work on opera, Kobbe's, skips from Param Vir to Amadeo Vives, as if Vivaldi's 50-odd operas didn't even exist. It's safe to say that nobody in Tuesday's audience has ever seen a production-or even heard more than a few minutes-of "Griselda," "Il tamerlano" or "Ercole sul Termodonte." Yet to judge from Bartoli's concert (and last year's revelatory CD of the same repertoire), the 21 surviving stage works include some mesmerizing lengths of music.

Some of it is familiar from other guises. The "Winter" Concerto, from "The Four Seasons," metamorphosed into the extravagantly mournful set-piece aria "Gelido in ogni vena," from "Farnace," in which the protagonist contemplates the body of his dead son. Bartoli, riveting in misery and infectious in exhilaration, made it a tour de force of lively tragedy.

She was, as always, irresistibly ungraceful. Even in a long Venetian dress, Bartoli had the demeanor of an athlete in an evening gown. She strutted downstage and assumed a bodybuilder's stance, shoulders hunched, neck stretched forward, knees slightly bent, spine curved into the hint of a C. She accompanied feathery trills with a chicken-like jerking of her head and pushed out her chest for a particularly heroic climax. Afterward, she urged the ensemble toward its final, frantic shudder with a right hook into the air.

All this hurly-burly might be annoying if it did not feel like the irrepressible physical expression of a woman who has music pulsing through her limbs. Bartoli projected the songs' assorted agonies and fury, but beneath it all was a bodily, even carnal delight in singing and the confidence of consummate control.