Music Review : Rostropovich: Greatness Under Stress : The artist returns to what he does best--play the cello--for a packed crowd at Ambassador Auditorium.

Mstislav Rostropovich is a great cellist. Everyone knows that.

Unfortunately, he hasn’t been content to be a great cellist. He devotes a lot of time these days to activities in which he is less than great--conducting, for instance. The results, though always interesting, are sometimes frustrating.

Under the circumstances, a simple cello recital by Rostropovich has become a special event--a rare opportunity for intimate communion with a master. Thursday night at Ambassador Auditorium, the master confirmed his unique qualities as an interpretive artist for an adoring crowd that spilled onto the stage.

Rostropovich remains a generous, discerning musician and, most gratifying, perhaps, one who dares to take chances. Unlike so many of the faceless wonders who have followed him, he illuminates every challenge with a powerful, personal vision. In a world dominated by superficial flash, he is a reassuring presence.

He invariably plays with fierce concentration and unbridled passion. For him, there is no other way.

At his best, his passion coexists with precision. At his worst, his passion takes a certain toll.

He wasn’t always at his best on Thursday. He produced his customary silken thread of sound in moments of reflection. He offered object lessons in lyrical sensitivity and poise in subdued passages, and invariably ennobled the line with telling expressive nuances. Under pressure, however, his tone turned alarmingly raspy and his intonation unreliable.

He disappointed some of his loyal followers, moreover, by repeating the exact program he had played a year ago in nearby Cerritos. We know he is a busy man, but. . . .

With Lambert Orkis providing sensitive accompaniment, the cellist began the evening with Richard Strauss’ F-major Sonata, written in 1882 when the composer was a precocious and somewhat bombastic 18-year-old. Rostropovich’s loose, quasi-improvisatory phrasing was appealing, as always. So was his sense of rapture. His stridency, however, proved disconcerting.

Matters improved in Bach’s unaccompanied Suite No. 5 in C minor, which challenged the cellist’s mind as much as his fingers and arm. Here, he clarified the structural complexities, sustained an aura of propulsion despite the detours and even found hints of drama amid the abstraction. A technical lapse or two seemed hardly relevant.

After intermission, Rostropovich and Orkis collaborated on a surprisingly gusty and gutsy performance of the impetuous yet eerie Debussy Sonata of 1915. In the process, they made the work’s general neglect all the more difficult to understand.

Then, as dangerous piece de resistance , they turned to the “Epilog” from Alfred Schnittke’s ballet “Peer Gynt” (1986). The Russian composer, indomitably progressive, created this transcription for cello, piano and tape in 1993 and dedicated it to Rostropovich.

The score involves a strenuous half-hour of thematic and dynamic convolution leading to a resolution of ethereal clarity. Cello and piano function as complementary protagonists one moment, as antagonists the next. Violent dissonance punctuates melodic innocence. The background tape, derived from chorus and organ, cloaks the central voices in a mysterious sonic haze. It is disturbing, fascinating, ultimately compelling.

Rostropovich played with conviction and pathos, occasional miscalculations notwithstanding. An apparent loss of control deprived the final lofty cadence of its ultimate pianissimo serenity. But the spirit was emphatically willing and, in context, that seemed enough.

Orkis provided an appreciative if muted counterforce at the keyboard. He was, perhaps, deferential to a fault.

In response to hearty but hardly overwhelming applause, Rostropovich mustered one encore: Bach’s Sarabande in D.