The Smithsonian Chamber Players, who for years have plumbed the depths of Baroque repertoire, have now turned their informed attention to the Classical period. Under the direction of scholar-performer Jaap Schroeder, and with a new name that befits the age they are honoring, the Smithsonian Chamber Orchestra played the first of a four-concert series at the Smithsonian's Baird Auditorium Saturday night.

The four concerts are avoiding the most widely heard pieces of the period in favor of its developmental signposts, arranged roughly in chronological sequence. Saturday's program featured a symphony by Johann Christian Bach, a marvelous "Concertone," actually a quadruple concerto from early in Mozart's career, and Haydn's Symphony No. 6, "Le Matin."

It took a while, through the Bach Symphony, for the orchestra to warm up. Schroeder plays the violin from the podium. His conducting is a byproduct of his bowing and associated body English, and the opening work needed a little firmer direction to propel it convincingly and to do visually for the orchestra what it was evidently having a hard time doing by ear alone.

The Mozart was an entirely different matter, however. From the opening bars, it moved with inner energy. Its ornamented lines had a crisp delicacy. The characteristic coloring of the ensemble by the wind contingent gave the sound a delicious astringency, and the ascendance of the two solo violins, oboe and cello was accomplished effortlessly over a sensitively balanced tutti force. Violinists Schroeder and Marilyn McDonald developed, over the course of the piece, into as finely matched a pair as one could hope for, with Schroeder's shining, agile lines answered by somewhat darker but as beautifully shaped phrases by McDonald. Oboist James Caldwell and cellist Kenneth Slowik played smaller but no less sensitive roles in the solo ensemble.

The Haydn Symphony, with its surprising solo opportunities and highly mannered inner movements, had a spirited reading.