The Houston Symphony Orchestra made one of its infrequent appearances here last night at the Kennedy Center in a deeply committed, emotionally engrossing performance of the Rachmaninoff Second Symphony under Sergiu Comissiona, its newly named music director.

The Rachmaninoff is a melancholy work, and one would not expect to hear a reading more brooding than last night's. The orchestral canvas was dominated by the low strings and brass. Tempos were very slow, and phrases were sometimes stretched just short of the breaking point.

Yet Comissiona and the players held it all together, with a masterly show of the slow-down/speed-up art of rubato.In the process, they probed remarkably deeply the manic-depressive moods that lie at the symphony's core. Often the emotional impact of the Rachmaninoff Second comes more from these startingly mercurial switches of mood, than from the composition's cumulative impact.

In this highly rhapsodic playing, precision was sometimes sacrificed to sustain a mood. The need for an overall sense of foreboding was placed ahead of virtuosic niceties of detail.

That was just as well because the Houston is not a powerhouse orchestra. It did not bring to the Rachmaninoff the sonic brawn or tonal refinement that one heard from the National Symphony under Eugene Ormandy just a few weeks ago. But neither did the National Symphony match the Houston Symphony's emotional depth.

Earlier on the program there were two Mendelssohn works, the "Ruy Blas" Overture and the Violin Concerto. Both had warmth and buoyance. The composer's irrepressible spirits flowed almost spontaneously.

The soloist in the concerto was Russian emigre Dmitry Sitkovetsky. He played the Mendelssohn with uncommon sensitivity. The phrases breathed with easy grace, always in proportion to the work's overall shape. Sitkovetsky is an instinctive lyricist, not unlike his more famous mother, pianist Bella Davidovich.

There was an occasional moment of roughness in the bowing, and Sitkovetsky's tone was sometimes curiously inconsistent. On the low G string his sound was sweet and rich, but the highest tones, on the E string, took on a glossiness that made them sometimes seem disembodied. No doubt the disparity was more a characteristic of the instrument than of the instrumentalist.