Most of the people came to hear Bach and Handel Thursday night in the Kennedy Center Concert Hall, but a lot of them stayed to hear Cole Porter and Irving Berlin. And some found themselves unexpectedly dancing.

After the first concert of the St. Paul Chamber Orchestra's three-day visit, the audience drifted out to the riverside terrace, where they had been told there would be some "light music" for their entertainment. There they found a small dance band (violin, accordion and guitar) playing old-time pop favorites.

An illuminated fountain cast a romantic glow on the scene, and a bar, coffee and desserts were available. Some of the patrons simply stood around, listening to the music and gazing at the Potomac, which becomes quite pretty after dark. But others began to dance, shyly at first and then in growing numbers. The music begged for it, the atmosphere (including ideal weather) was just right, and the marble pavement of the terrace is as danceable as a waxed hardwood floor -- considerably more danceable than the rug indoors where thousands of people come for a free dance party every New Year's Eve.

"We hope this will grow into something like our 'Night in Old Vienna' parties," said Marta Istomin, the Kennedy Center's artistic director, smiling at the dancing couples. "It's only the beginning, and we plan to have dancing every night of our Summer Nights by the River Festival." The festival and the dancing will resume when the Mostly Mozart Festival opens at the Kennedy Center June 25.

Meanwhile, the St. Paul Chamber Orchestra opened its 300th-anniversary tribute to Bach and Handel with a neatly varied and generally well-performed program.

The music was best in the first half, opening with one of Mozart's tributes to Bach, the magnificent Adagio and Fugue in C minor, K. 546, beautifully played by the string section with Stanislaw Skrowaczewski conducting. In the Concerto No. 1 in D minor, pianist Jean-Bernard Pommier pleaded eloquently for the piano's rights in the music of Bach. His performance was scaled to Baroque proportions, though the instrument was much more clearly audible than a harpsichord would have been in the large concert hall. On a harpsichord, Bach becomes a composer precisely located in a historic context. In a good piano performance (and Pommier's was outstanding), he sounds more like a composer looking to the future -- a more universal artist. The effect was refreshing and the concerto sounded more interesting than it has (to me, at least) in years.

After intermission, soprano Marvis Martin sang three vocal works of Bach and Handel with exquisite style, striking stage presence, opulent tone and occasional, slight imprecisions of pitch. Bach's Third Suite for Orchestra concluded the program in a performance that sometimes sounded underrehearsed and lacking in focus.

Lack of rehearsal was also evident in Saturday night's concert, with Pommier conducting the Brandenburg Concertos 1, 2 and 5. The evening opened with No. 2, played rather too fast and marred by ensemble problems in the first movement -- followed by an exquisite interpretation of the slow movement. The opulent No. 1 gave the evening a happy ending in a smooth, mellow performance. In between, Pommier played brilliantly but idiomatically as piano soloist in No. 5.