MUSIC REVIEW : Virtuoso Falls Short of Repute : Stage: French flutist Jean-Pierre Rampal lacked focus in San Diego Chamber Orchestra concert.

Instrumentalists rarely suffer the fate of divas,whose vocal gifts tend to fade long before they are ready to retire from the stage. But French flutist Jean-Pierre Rampal’s performance Monday night with the San Diego Chamber Orchestra resembled an aging diva’s attempt to cope with diminishing faculties.

Of course, it is entirely possible that the noted 69-year-old flutist was merely experiencing an off night as he labored through Mozart’s oft-played G Major Flute Concerto, K. 313, and Telemann’s deservedly obscure D Major Flute Concerto. For the most part, Rampal gave Telemann’s predictable Baroque formulas and banal echo motifs dutiful execution. His trademark timbre, however, lacked consistent focus and sounded unusually edgy. With his eyes glued to the score, he seemed uncomfortable both with the uninspired concerto and music director Donald Barra’s labored interpretation of the piece.

With the Mozart Concerto, Rampal returned safely to familiar musical territory. To the slow movement’s cantilena he brought his wonted silver tone and soaring lyricism. He traversed the long lines of the outer movements with clarity and vitality, although the final notes of lengthy roulades tended to get smudged. It was vigorous, old-fashioned Mozart playing, the sort that Rampal has amply documented on disc over his lengthy career. The orchestra’s accompaniment was both colorful and sympathetic.

Barra opened the concert with a spirited, cleanly articulated reading of J.S. Bach’s Suite No. 1 in C Major. The chamber orchestra exhibited unusual clarity and balance, relishing the work’s endlessly inventive counterpoint. Bassoonist Britt Herbert and oboist Peggy Michel infused their solo sections with the graceful melodic sweep and rhythmic accent appropriate to each of the suite’s dance movements. If the string ensemble had faithfully mirrored their stylish inflections, it would have been the best of all possible Baroque worlds.

In Mozart’s brief Divertimento in F Major, K. 138, Barra confused speed for vitality, giving the modest bauble a nervous, under-rehearsed quality.