Bach's six "Brandenburg" Concertos were composed as part of his quest for a new job, and they are a convincing demonstration of his orchestral genius. They are so varied in form and instrumentation that they could make a splendidly diverse concert program all by themselves.

That doesn't happen -- because the music runs far past the two-hour mark (particularly if you play all the repeats) that has become the de facto limit for most orchestral concerts. But on Sunday afternoon in the Schlesinger Concert Hall of Northern Virginia Community College, the Eclipse Chamber Orchestra came close. A half-hour was added to the usual time limit, and the players managed to include all the "Brandenburgs" except No. 2.

They were arranged to maximize contrast: the stately No. 1 and the giddily brilliant No. 5 before intermission; the traditional No. 3, the mysterious, low-voiced No. 6 and the lilting, flute-driven No. 4 afterward.

The result was an unalloyed delight. This is some of the most enjoyable music ever composed, and the players (members of the National Symphony Orchestra and one or two close associates) are among the finest musicians in Washington.

They approached the pieces as chamber music, interacting smoothly without a conductor, though their regular conductor, Sylvia Alimena, kept busy backstage, making sure that the changes of personnel for each concerto went smoothly. Bach composed this music for a virtuoso ensemble, and nearly everyone (far too many to name) had a delectable solo. This tiny, highly skilled orchestra adds enormously to the joy and variety of the city's musical life.

-- Joseph McLellan

The Eclipse Chamber Orchestra pulled together five of Bach's six "Brandenburg" Concertos.