Sylvia Alimena concluded her nine-year tenure as music director of the Friday Morning Music Club with a boom yesterday afternoon. Or, rather, with a series of booms -- the 16 timpani crashes that pulsed through the Church of the Epiphany and brought the Symphony No. 3 in C ("Organ") by Camille Saint-Saens to a rattling, jubilant close.

It was an exciting concert in many ways, not only in and of itself but because of what it seemed to promise for both Alimena and her ensemble.

In the past, Friday Morning Music Club performances have generally come in on the proverbial "wing and a prayer," and the group has sounded exactly like the motley, every-now-and-then collection of good-to-middling musicians that it is. Yesterday it sounded like a genuine orchestra -- not always the most polished ensemble in the world, mind you, but an orchestra all the same.

The brass antiphonals in the final movement of the Saint-Saens rang out with brilliance and bite, while the strings in the slow movement were charged with a near-Mahlerian languor and yearning. Whatever the playing may have lacked in polish (and most of it was really pretty solid) was more than made up for in energy and urgency.

Alimena herself goes from strength to strength. She will now take over the directorate of the McLean Symphony while continuing to direct the Eclipse Chamber Orchestra and play in the horn section of the National Symphony Orchestra. Her leadership yesterday was vigorous and knowing, and she extracted eager, impassioned playing from her forces. The audience whooped as the last notes of the Saint-Saens died away -- and rightly so, for this was a triumphant performance.

The program began with the Concerto No. 2 for Organ and Orchestra (Op. 177) by the German composer Josef Rheinberger (1839-1901). I can think of only two reasons to explain why this bejeweled work is not better known -- namely, the necessity of bringing together organ and orchestra in the same place (not always an easy task) and the composer's relative obscurity in the classical pantheon (Rheinberger's name will sell no tickets). The piece itself is a beauty, filled with lofty, serene melodies that combine the formal concision of Mendelssohn with some of the windswept, autumnal melancholy of Brahms. Even the finale's occasional bombast is enjoyable in its own gruff way, and it passes quickly. This is altogether lovely music, attractive enough to make a listener wonder where Rheinberger has been all his life.

Eric Plutz, the spirited and virtuosic organist, is also the person in charge of all musical performances at the Church of the Epiphany. The series of free "lunchtime" concerts that the church presents every Tuesday, a few minutes after noon, is one of the hidden joys of musical life in Washington and a marvelous escape from the summer heat. Information: