For its size, Boston already has a disproportionate share of extraordinary musicians and ensembles, so it's always a little surprising when another group appears, and immediately takes a place at the head of the pack. Yet that's what's happened with the Boston Trio, which conquered Tanglewood a year ago, and added Jordan Hall to its conquest Sunday afternoon.

The trio comprises pianist Heng-Jin Park Ellsworth, violinist Lucia Lin, and cellist Andrew Pearce. Between them, they hold a passel of impressive professional affiliations, competition honors, and pedagogical pedigrees, all of which one expects of leading performers, but none of which guarantees the kind of unified purpose that one has to obtain for really fine chamber music. These three do play with purpose, passion, and points of mutual contact. One may not always concur with their readings, but there is no faulting their solidity, and no escaping the sense of their commitment and intent. If one were to suggest any wholesale refinement, it would be to lavish a little less refinement on some pieces.

That would certainly not be an appropriate recommendation for their performance of Beethoven's youthful, sunny Trio in B-flat Major, Op. 11, which was taut, technically brilliant, witty, and winning in nearly every respect. The adagio was especially fine, Pearce's gorgeous, singing tone in the opening contrasting effectively with Lin's slightly colorless echo. Ellsworth's playing throughout the concluding set of variations was dazzling.

A late contender for the best-of-1998 roundup, their performance of Ravel's Trio in A Minor was superb on so many levels. Because of the shared language of Impressionism, Ravel is too easily clumped with his elder, Debussy. But instead of breaking with the 19th-century virtuoso tradition, Ravel's music springs stylistically from it, while borrowing formally and spiritually from classicism. This is to say that the virtuoso works, of which the trio is a major example, have to combine the panache and verve of, ay, Rachmaninoff, with the lucidity of Haydn, and that's what this performance did.

Ellsworth's opening was beautifully and subtly phrased, and set exactly the right tone for this most sensual of the four movements. The Pantoum was delivered with extraordinary vitality, and the monstrously difficult finale was among the most buoyant, least labored this listener has heard.

Charles Ives's "Piano Trio," while exuberantly played, was yet too restrained and modest, and Paul Schoenfield's salon pastiche "Cafe Music," for all the benefit it derives from virtuosi, actually suffers a little from performers too well schooled.