Although it was first performed by the Empress Maria Teresa's daughters, the score features some demanding vocal writing, particularly in Apollo's first aria. Mitzie Kay Weiner plunged into the coloratura forcefully and managed the runs with a rich vibrato, although a lighter voice would perhaps have sounded more graceful and Olympian. Still, Weiner sang a controlled long line, showing impressive breath control in both her arias.

As Erato, the muse who sings "Di questa cetra," Elspeth Franks gave another sterling performance, her vibrant tone matched by superb legato. She obviously enjoyed the give and take with the other characters. Rita Lilly, as Euterpe, muse of music, was equally stellar, her vocal quality pure and light but with plenty of color (and not at all boyish, like some early-music sopranos). Carole Schaffer, as Melpomene, muse of dramatic poetry, completed the quartet. She displayed a generous voice apt for the stormy music (with accompanying horns) of her first aria, on the tempest-tossed-boat simile so essential to opera seria. Here, of course, the simile aria is presented with a slightly arched brow, a facet that Ms. Schaffer also underlined in her second aria in which the muse (briefly) swears off writing poetry.

If you find your scorecard getting full with the Bay Area's proliferating early-music groups, don't bother cudgeling your brains too much: the CCOO, like many other groups, drew its players for this concert largely from the Philharmonia Baroque and American Bach Soloists. Familiarity with the style and with each other is probably one reason that they played the score with such ease and polish. Aside from a couple of slightly loose down-bows in the overture and the first aria, the orchestra was perfect. In the live acoustic of St. Mark's, the horns were bound to be a little overweighted, but the balances were generally excellent. Gilbert Martinez and Scott Shubeck gave nuanced support in the recitatives, and Carol Panofsky contributed a beautiful oboe solo in Euterpe's aria.

As for Mr. Busse, he showed a solid conducting technique, seemed to respond to what he heard, and controlled the performance without overt histrionics. More to the point, he is an industrious entrepreneur, an essential quality in any young conductor. You have to admire his ambition and confidence, which should serve him well in the future.