Music : ‘Brandenburgs’ by Brown, LACO

Different families celebrate the year-end holidays in different ways. Some roast a goose and prepare the fixings; some fly away to a Caribbean island. For a long time now, the Los Angeles Chamber Orchestra family has observed the year-end by presenting, at its separate performing homes, Bach’s six “Brandenburg” Concertos.

To this tradition, over the weekend, came Iona Brown, now in her second season as music director of the ensemble. At Royce Hall on Friday--with repeats scheduled in La Jolla on Saturday and at Ambassador Auditorium on Sunday and tonight--Brown led the cycle with her familiar combination of stylishness and panache.

At the first event in this series, however--Brown’s reported first public performance of the works as a group--exhibited an edge of nervousness. Not all the elements seemed comfortably in place, not all tempos spoke convincingly. For an ensemble that has proved expert at these works for more than a decade, these performances emerged less than authoritative.

Nevertheless, they had their moments, especially after Nos. 3 and 6--the first to be performed--were safely out of the way.

When the entire orchestra convened for the Concerto No. 1, in F, and flexed its collective musical muscles, the project seemed launched at last. Here was aggressiveness and competitiveness, the twin goads to adrenaline, and here was the real Bach, stating his case.

Thereafter, conviction--if less than completely transparent textures--characterized the readings. With flutists David Shostac and Susan Greenberg, and violinist Brown, as the three soloists, the combined forces sailed joyfully through No. 4, despite shakiness in the finale. Then, with flutist Shostac, harpsichordist Patricia Mabee and fiddler Brown leading the way, the countless dangers in No. 5 were crossed and left behind.

Best, as it can often be, was the pleasureful plateau of No. 2, in which fearless trumpeter Roy Poper--who has certainly done this before, and with equal success--oboist Allan Vogel, Shostac and Brown dispatched their solo duties like happy survivors. Afterward, their colleagues in the orchestra shared in the general rejoicing.