Amsterdam Baroque Orchestra at Alice Tully and in Newark On Thursday evening at Alice Tully Hall, Bogna Bartosz was singing the alto part in Bach's Magnificat in D (BWV 243). Her aria, "Esurientes implevit bonis," comes near the end, and she dispatched its burbling runs with perfect evenness. Not a single note popped out or receded unduly: the line was one scrupulous, straight shot. The technical feat was so satisfying, and Ms. Bartosz's tone so gentle and softly burred, that it was only toward the end of the aria that I realized how detached I was from it, how cool the emotional temperature was. This was the problem in Thursday's concert, at which Ms. Bartosz and three other soloists appeared with the Amsterdam Baroque Orchestra and Choir under the direction of their founder, Ton Koopman. In the Magnificat and two of Bach's sacred cantatas, the ensemble was never less than polished and skillful, with well-chosen tempos and precisely calibrated swells. But the performance was also mellow and buttoned up: as well made, sensible and tame as a Tod's loafer. It took 24 hours and a change of auditorium - a change of state - to transform matters entirely. On Friday evening the orchestra and choir, with Mr. Koopman and the same soloists, took the stage at the New Jersey Performing Arts Center in Newark for Bach's Mass in B minor. There is no reason Amsterdam Baroque should have been more effective there than at the intimate, Baroque-scale Tully Hall, which has 1,100 seats, against the 2,800 in Newark. And Mr. Koopman and the performers hadn't changed their style. The performance was still a slow, steady burn rather a series of fiery bursts. But on the broader canvas of the B minor Mass - just about the broadest canvas music offers - Mr. Koopman's patience, and his careful sculpturing of each section, resulted in something memorable. While the polish was still there, by the end of the two-hour work there was also an intensity and accumulated power that had been missing the night before. The burst of the "Et resurrexit," you learned, is more meaningful when the preceding two choruses have been so hauntingly understated. Mr. Koopman guided the ensemble with startling drive through the dense, slowly colliding harmonies of the "Confiteor," and the second choral "Kyrie" ebbed and flowed like a breath over a carpet of velvety playing from the trumpets. The orchestra played with flexibility and transparency in both concerts. Without distortion or overemphasis Mr. Koopman gave every detail its proper place: the pulsing in the woodwinds under the aria "Beglückte Herde, Jesu Schafe" in the Cantata No. 104 ("Du Hirte Israel, Höre"); the little flute chorale in the opening chorus of the Magnificat; the folksy lilt of the accompaniment to "Et in Spiritum Sanctum" in the Mass. In the "Christe" duet that follows the Mass's opening choral "Kyrie" Ms. Bartosz's voice blended with the soprano Teresa Wakim's with the combination of sensuality and purity that is the paradoxical ideal in Bach's sacred works. The tenor Tilman Lichdi - who had raged through "Hilf, Jesu, hilf" in the Cantata No. 147 ("Herz und Mund und Tat und Leben") - had a clear, earnest sound, and the bass-baritone Klaus Mertens sang on both Thursday and Friday with conversational naturalness and warm eloquence. The choir was the glory of both performances, its sibilants crisp and its sound penetrating, particularly in the high voices. By the last sequence of the Mass, starting with the Sanctus, it was in a deep groove, with the orchestra joining it in a second "Osanna" that was as raucous as this ensemble becomes. If some of us may have wanted this final celebration to be rowdier still - even delirious - that is not the way of the serenely, sometimes sublimely moderate Mr. Koopman.