It wasn't hard to know that yesterday was Johann Sebastian Bach's 300th birthday. Bach had been on all the morning news shows. There was hardly anything else to hear on any of the classical music radio stations. He had also ended the "NBC Nightly News" the evening before in a substantial, and excellent, segment.

Of yesterday's events here, the most extravagant was a free, three-hour lunchtime concert -- a long lunch -- at the Western Presbyterian Church. Four local organizations and two soloists presented a cross-section of the composer's almost unprecedentedly varied output. Listeners lined the aisles and overflowed into the lobby.

There were concertos, organ works, an unaccompanied cello suite, an orchestral suite and vocal works. In three Lutheran hymns, conductor Paul Hill led the audience. "Wake, Awake, for Night is Flying" (for which texts were handed out) was followed by the famed chorale prelude based on it, played splendidly by Sondra Proctor.

The concertos came off the best, especially in a taut, well-phrased performance of the Double Concerto for oboe and violin by the Levine School Chamber Orchestra under Michael Morgan. It was a student orchestra, but Morgan made it buoyant and finely honed, playing right on the beat. That is a characteristic as important in Bach as in rock. And young oboist Gonzalo Ruiz was the star of the concert. His full tone was consistent and phrased with grace.

The group called Hesperus played the Sixth "Brandenburg" Concerto, the dour one for the low strings that often takes the form of an eloquent viola duo. It was not the most polished playing, but it had a highly inflected intensity. Polish may have been beside the point anyway, pitted against a crying baby (throughout the three hours) and the general hustle and bustle in the 500-seat church, which is next to the World Bank.

The Third "Brandenburg" was also played, by members of the Kennedy Center Terrace Theater Orchestra. This is one of the most richly harmonized of the concertos. The performance was nicely pointed.

The Terrace players also performed the Second Orchestral Suite, which is a sort of extended flute concerto. Sara Stern played the flute part with warmth, but less brio.

Cellist Evelyn Elsing performed the C major solo suite, full of graceful tunes and dance rhythms, with verve.

Paul Hill led a small group of singers from the Paul Hill Chorale in "Break Forth, O Beauteous Heavenly Light" from the Christmas Oratorio and in two excerpts from cantatas, including "Sheep May Safely Graze," all impeccably performed, in English.

Organist A. Graham Down played several organ pieces, including the virtuoso Fantasia in G.

There was even a cake to observe the day. And Mayor Marion Barry sent a proclamation declaring it to be J.S. Bach Day, declaring the composer's gift "a genius that remains unexcelled . . . whose work continues to lift our spirits and bring joy to the world."

For birthday music, the ebullient spirit was right.