The Washington Chamber Society began, a few years ago, by giving free concerts in churches. Now it charges a modest admission fee, but it still plays to capacity audiences. Modeled on the Chamber Music Society of Lincoln Center, it does not match the glittery reputations of its colleagues to the north, but its members are solid, dedicated musicians, and Saturday night at Wesley United Methodist Church on Connecticut Avenue they gave an extraordinary performance of the Brahms Clarinet Quintet.

It was not a matter of dazzling virtuosity -- it is not that kind of music -- but of total involvement; every phrase carefully weighed and balanced, deeply felt and eloquently stated. The five musicians interacted with one another and with the music on the deepest level of intensity, yet the impression was one of tightly exercised control. The impact was enormous. In the Mozart Clarinet Quintet, which opened the program (exhausting the world's supply of transcendent masterpieces in that form), the interpretation was more restrained, concentrating on the cool, formal beauty of the music and providing a neat contrast to the Brahms.

At the center of attention was clarinetist Charles Stier, a Washington musician primarily identified with contemporary music but equally adept in the classical repertoire. He played beautifully throughout, but interacted with the string quartet in a free dialogue of equal partners. The four string players, all excellent, were cellist Neale Perl, a cofounder of the Washington Chamber Society, and violinists Elisabeth Adkins and Jane Bowyer Stewart and violist James Francis. These three are all relatively new members of the National Symphony Orchestra, and they help to explain why it has been improving so spectacularly.