What can you say about a performance of Robert Schumann's Piano Quintet in E-flat on a program that is titled "Mostly Mozart"?

Last night, you could have said Schumann completely stole the show from the namesake of this week's festival in the Kennedy Center Concert Hall. Even with the addition of a string quartet by Mozart's friend and mentor Haydn, the musical and emotional impact of last night's performance by the Tokyo String Quartet and guests was mostly Schumann.

There were various reasons for this effect, including prominently the ingenious forms and impassioned rhetoric of Schumann's moody masterpiece, one of the 19th century's most effective pieces of chamber music. In this performance, the music's impact was enormously enhanced by the addition of pianist Bella Davidovich to the Tokyo ensemble. Sometimes her instrument was balanced with the strings, sometimes pitted against them in striking contrast; occasionally, she took the lead and a few times she uttered what might have been a protest.

In any case, the emotional climate in the Concert Hall warmed up perceptibly as soon as her hands touched the keyboard. Her presence (and, of course, Schumann's music) seemed to infuse new vitality into the strings, which had been precise and exquisitely musical but rather cool and remote in the 18th-century pieces played before intermission.

In the first half of the program, it sometimes seemed (as it often does when a quartet or trio is playing in the Concert Hall) that the auditorium was just a shade too large for the musical forces on the stage. The result was that Haydn's charming, inventive Quartet in G, Op. 77, No. 1, and Mozart's magnificent Quintet in C, K. 515 (with Raphael Hillyer as second violist), had plenty of clarity but not much impact--certainly not what they would have had in the Terrace Theater, for example.

A special shell for chamber ensembles, to project their sound more vigorously into the audience, might help this situation. But it would have been better if the Tokyo Quartet had adopted for this music a slightly larger scale of dynamics, similar to what it used so effectively in Schumann. This would undermine the 18th-century style that the quartet cultivates with a fair approximation of authenticity, but it would recognize that the 18th-century music is being played in a 20th-century environment.