Last Monday, the week of free Mozart birthday concerts at the World Bank began with a standing-room-only house. By the concluding event at lunchtime Friday, the crowd was not just in the new auditorium but poured well out into its lobby.

The final program was the most symphonic in this chamber music series. Piano was pitted against a quartet of oboe, clarinet, bassoon and horn -- that classic Mozart pairing that reaches its greatest peak not in his chamber music but in the 27 piano concertos, with their intricate interweaving of the winds and the solo instrument. No other composer so fully grasped the distinctive possibilities of a wind quartet, by comparison, for instance, with the string quartet. Not only is there the wide range of pitch, but also an even wider range of timbre -- from the pinched oboe to the sonorous horn. They are like four different characters in an intimate drama.

In the last movement Friday from the E-flat Sinfonia Concertante, the bassoon sang free in the second variation, but by the eighth it was combined in an utterly different character with an ornamental oboe on arpeggios. Mozart adored this savoriness.

Friday's players were from the National Symphony: Richard White (oboe), Lawrence Bocaner (clarinet); Louis Lipnick (bassoon), Daniel Carter (horn) and pianist Andrew Litton, the orchestra associate conductor-to-be. They reveled in the music's parade of textures.

The work that concluded the concert is one of Mozart's grand achievements, the E-flat quintet, K. 452, which he described in a 1784 letter to his father as "the best work I have so far written in my life." That's going a little far, but the enthusiasm is understandable.

This was the second year for a Mozart birthday series at the World Bank. Given its popularity, there should be no reason to limit concerts there just to Mozart, or just to the last week in January. In his remarks Friday, Richard J. Osius, the managing director of the Bank-Fund Credit Union, which helped pay the bills, suggested similar series for Bach, Schubert and Beethoven. Already there is an effort to organize a Scarlatti festival for his 300th birthday in October.

Even if the festival sticks to Mozart, there is plenty of fine music to fill years of events. In his program notes, Theodore W. Libbey Jr. observes that one of the distinctive features of Mozart's "universality" is that "if every trace of his chamber music disappeared tomorrow," he would still be Mozart -- in the operas, the symphonies, the concertos, and so on. Perhaps. But if nothing but the chamber music survived, he also would still be Mozart.