Perhaps the happiest musical news of the past year has been the spectacular return of pianist Leon Fleisher, who damaged his right hand severely back in the early 1960s and has only recently recovered its use.

Last night, Fleisher played Beethoven's Piano Concerto No. 5 in E-flat ("Emperor") with the National Symphony Orchestra at the Kennedy Center, under the direction of Leonard Slatkin. It was for the most part a beautiful performance -- proportionate, supremely intelligent, yet ripe with feeling. If Fleisher's right hand has not yet achieved full parity with his left, this remained a performance of which any pianist would be proud, and I expect the long, soulful meditation that Fleisher made of the central Adagio to haunt me for days.

Still, I hope it will not seem callous to suggest that the expansive and treacherously difficult finale may be unduly wearing for Fleisher at this point. The man who can work such magic with tender filigree -- somebody who can take almost anything and make it more musical -- should not risk working himself so hard as to suffer any sort of relapse, and there were marked signs of strain in the finale. There are many great pieces -- yes, just as great as the "Emperor" -- that do not demand such muscularity (think of the late Mozart concertos, just for a start). Now that we have Fleisher back in our midst, I want to keep him around as long as possible, and I am happy to leave the grandest technical challenges to other pianists.

This was the NSO's first concert with Slatkin since it was announced that the conductor would step down as music director at the end of the 2007-08 season. Perhaps that was one reason why the musicians played for him with such intensity throughout the evening (at a rehearsal yesterday morning, he was greeted with a prolonged standing ovation).

Stravinsky's "Rite of Spring," which closed the program, was a riot of nerve endings and glorious noise -- from the opening, capon-like cry of the throttled bassoon at the uppermost extreme of its register through the shattering thud that brings the music to a close 35 minutes later.

The program began with the American composer Donald Erb's "Evensong." Slatkin preceded the performance of this 1993 piece with an odd little speech, claiming that Erb's music, like that of Beethoven and Stravinsky, was recognizable as uniquely his within a few seconds of the beginning of any piece.

Funny, but I listened to all 23 minutes of "Evensong" without getting any real sense of what Erb is about. At times, it sounded like Edgard Varese with tunes; other times, I was reminded of the work of Joseph Schwantner or Jacob Druckman or any number of other composers who wear their orchestral virtuosity on their sleeves. It's all very well done in its way -- and a terrific challenge for a virtuoso orchestra, which the NSO has certainly become under Slatkin -- but I had the recurring sense that I was listening to a demonstration of acoustic principles, rather than to any sort of vital, personal expression.

The concert will be repeated this afternoon at 1:30 and tomorrow night at 8.

Backed by the NSO, Leon Fleisher continued his spectacular return to playing after recovering from the neurological problem that had crippled his right hand 40 years ago.