t a time when America's major orchestras are struggling to define their missions and maintain audiences, the San Francisco Symphony under Michael Tilson Thomas is an exception. Concertgoers there are younger and have embraced Mr. Thomas's adventurous programming. The orchestra is considered an artistic beacon not a cultural relic.

So, there was naturally a palpable sense of expectation in Carnegie Hall for the concerts on Wednesday and Thursday nights by the San Francisco Symphony, which for the first time had brought its resident chorus (Vance George, director) to New York. Would Mr. Thomas's success with the orchestra come through away from home? Would New York audiences be dazzled?

If the concerts were not quite dazzling, they were impressive over all and quite interesting. Wednesday night's Stravinsky program began with the infrequently heard "Perséphone," a 1934 melodrama on a text by Gide. The stylistically eclectic score, with its hints of Russian folk dance and French chanson, is awash in consonance and purposefully lacking in tension.

Though a tenor is singing narrator, most of the text in the word-driven work is delivered by a speaker, here Stephanie Cosserat, a captivating actress.

So the music became all. Mr. Thomas drew lushly beautiful playing from the orchestra and rich, alert singing from the chorus, fortified by the American Boychoir. The tenor Stuart Neill negotiated the skittish vocal lines heroically. Yet the playing could have used more emphasis and definition.

"Les Noces," Stravinsky's cantata about the frenzied preparations for a Russian peasant wedding, was presented here in its seldom-heard original 1917 version for orchestra with extra winds and, for exotic color, the zitherlike cimbalom. The music's driving rhythms have more punch when hammered out on four pianos in the familiar 1923 version. But in this original scoring the raucous winds, tinny cimbalom and clattering percussion provided a different kind of vitality. The chorus and vocal soloists (Susan Narucki, Nadezhda Serdjuk, Viktor Lutsjuk, Sergei Aleksashkin) sang with almost scary fervor. The concert ended with a bold interpretation of the Symphony of Psalms, in which Mr. Thomas encouraged the nearly 120 choristers to sing out robustly, making this sacred symphony seem an anthem of fear and exultation.

Thursday night's Mahler concert began with a luminously played performance of the Adagio from the Tenth Symphony. Mr. Thomas brought rare cohesiveness to the circuitous melodic spans of this ruminative 30-minute work. He concluded the program with an arresting account of the hyper-dramatic "Das Klagende Lied," a 60-minute fairy tale cantata completed when Mahler was only 20, though later revised. Mr. Thomas, the chorus and the orchestra treated this ambitious, astonishingly well-orchestrated and overlooked score with utter respect. The fine vocal soloists were Christine Goerke, Michelle DeYoung, Jon Villars and Clayton Brainerd.