The Chamber Music Society of Lincoln Center performed last night in a quietly opulent, wood-paneled 19th-century English drawing room -- a wall of shelves filled with leather-bound books to the left, a medieval tapestry to the right and, behind them, a large, gilt lion-and-unicorn emblem hanging over the double doors.

The scene was the set for the beginning of "A Partridge in a Pear Tree," which was left in place for last night's gala inaugural chamber music concert in the Eisenhower Theater, and it proved an atmospheric setting for an evening of distinguished music-making. With this substantial set in place, the Eisenhower turned out to have probably the best acoustics for chamber music of any hall in the Kennedy Center. President-elect Ronald Reagan dropped in for the first two items on the program, delaying the start of the concert by 25 minutes and staying for about half an hour.

He heard good performances of two compositions, Copland's Duo for Flute and Piano, played with drama, wit and precise coordination by flutist Paula Robinson and pianist Charles Wadsworth, and Schubert's Sonatina in D played by two guest artists, violinist Lorin Maazel and his wife, pianist Israela Margalit. For his Eisenhower Theater debut as a violinist, Cleveland Orchestra conductor Maazel had picked a work of relatively modest technical demands but one that requires a fine stylistic sense. After a slightly tentative approach to the opening bars, he rose superbly to this requirement, producing light, rich tone and articulating most of the lines exquisitely, though his phrasing took on a non-Viennese squareness occasionally in repeated patterns.

Other commitments on this three-ring evening kept Reagan from hearing the best two pieces on the program. First was Ravel's Piano Trio in an expert performance by violinist Ani Kavafian, cellist Leslie Parnas and a guest artist, pianist Horacio Guttierez, which was marred only by a few moments in which the piano outbalanced its partners.

In the concluding number, Mendelssohn's Octet, the ensemble's regular members, Parnas, Kavafian and violinist James Buswell, were outnumbered by guest stars, violinists Glen Dicterow and Ida Kavafian, violists Scott Nickrenz and Marcus Thompson and cellist Lynn Harrell, but the pickup ensemble played together as though they had been doing it for years -- sometimes even slipping into the kind of synchronized bowing one expects in orchestral music but not in chamber music. Particularly delightful ws the gossamer sound of the scherzo and the agility with which the players tossed short phrases to one another in lighter moments of the dramatic finale.

The players may have felt that some of the finesse in their performance was wasted in a hall that was less than one-third filled (though every ticket had been sold) on an audience so unaccustomed to chamber music that it applauded after the first movement of each work. But the audience reaction was as enthusiastic as the music deserved -- which is very enthusiastic indeed.