LENOX -- The throng that packed the Koussevitzky Music Shed for the Beethoven Ninth Sunday afternoon clearly did not wait around until nightfall for the later jazz concert. But the smallish group that did welcome the Monty Alexander Trio in Ozawa Hall made up for its sparse numbers with enthusiastic applause and was suitably rewarded by the pianist and his sidemen.

Alexander began life in Jamaica, and his pianism bears an agreeable swinging Caribbean influence, but the elegance in which he embraces the keyboard in every manner possible reflects the early lessons in classical music he received before moving on to jazz piano at 14, and the clubs that soon followed.

He was joined on this occasion by Hassan Shakur, a bassist who manages unexpected sounds from an instrument often consigned to musical huffing and puffing, and Obed Calvaire, a drummer who has discovered the subtleties of his instrument set underneath all the customary bombast.

Sunday's program offered a 90-minute set of familiar tunes and a few more obscure, beginning with a cunning overture built around "I Got Rhythm" with Calvaire making his appearance initially in some solo riffs, with Shakur soon joining to pluck a few significant chords before Alexander entered the scene and folded himself into the music.

Alexander's own compositions, such as "Look Up" and "Hope," offered early in the proceedings, are quite listenable, but certainly not pedestrian, tendering lush textures and rich ornamentation, an obvious reflection of that early grounding in the classics, especially the Romantics.

His "Just Wait," he confided, came to mind after a successful bout with cancer. "Night Mist Blues," the tune by Ahmad Jamal, reportedly a big influence in his life, was given sweet mellow treatment before an up-tempo shift into some fanciful stride piano.

A tribute to another hero, Frank Sinatra, who Alexander reported discovered him when the two were playing in adjoining Miami club rooms, emerged from Alexander's keyboard not just as a song that "Old Blue Eyes" happened to sing. "Come Fly With Me," in Alexander's hands, pulsated with the unmistakable Sinatra sense of rhythm and phrasing. It was a loving tribute.

n

Alexander proved a generous leader, encouraging his colleagues into the spotlight. At one point, he left the piano for nearly eight minutes, standing aside, as Shakur was coaxing some fascinating tones out of his bass, including Henry Mancini's "Pink Panther" theme, which kept leaping from nowhere onto his fingerboard, while Calvaire kept time punctiliously with his woodblock.

In a nod to Jamaica, Alexander began a performance of "Day O" ("The Banana Boat Song") on his melodica, a keyboard wind instrument, employing it skillfully to its limits, then seamlessly shifted to the piano for all the upward modulations that bring the tune its glory.

n

Three encores included Alexander's rousing arrangement of "The Battle Hymn of the Republic," especially appropriate for the weekend commemoration of the 50th anniversary of the March on Washington led by Dr. Martin Luther King; "Sweet Georgia Brown," which darted all over the keyboard, with Calvaire's drum set finally let loose; and Alexander's tune, "The River," offered as a tribute to the memory of several artists, including Marian McPartland, the great jazz pianist who passed away last week.

The song, built around a simple melody embellished with cascading clusters of notes, conjured joyful memories of McPartland on the radio each week and at Tanglewood concert broadcasts in earlier years. Like McPartland, Alexander is a joyful music-maker.