At the Kennedy Center Terrace Theater Friday, conductor Stephen Simon opened the Washington Chamber Symphony's season with the Bach Suite No. 3 in D, Brahms's First Serenade and Beethoven's Piano Concerto No. 5 ("Emperor").

This is music to test an orchestra's finesse, and the WCS generally bore up well. The brass were robust, the winds full-bodied and meticulous, and the strings, though dry in tone, were bursting with vitality.

Simon is not one for indulging a juicy rubato or coaxing an improvisatory feeling from his orchestral soloists. Friday brought fleet tempos (slow movements were lithe and unsentimental) and phrasing that was scrupulously calibrated.

Simon's rock-steady beat and sense of musical architecture paid the greatest dividends in an exhilarating, historically informed performance of the Bach suite. The Brahms may have been more affectionate, but this classically poised reading was refreshingly light on its feet, channeling Mozart's spirit as well as Schumann's.

Pianist Jan Jiracek--more an invigorating conversationalist than a firebrand or philosopher of the keyboard--played an elegant, engaging "Emperor," partnered beautifully by Simon and his band.

For an encore, Jiracek reemerged with trumpet in hand (!) and joined the brass section for a Brahms Hungarian dance. Surely a first.