WALNUT CREEK, CA—The California Symphony served up a twin-barreled surprise March 27 that went well beyond expectations.

No sooner had they served up the amazing world premiere by Katherine Balch two years in the waiting than, before the applause had even died down, a fire alarm was set off, forcing every one out in the street cooling heels figuratively and literally.

We should make clear that the fire alarm, which arriving firemen proved false, was not a part of Balch’s magnum opus called “Illuminate.” But it surely made for an exuberant finale to an engrossing 28-minute piece. Balch, 30, has a gift for complex orchestrations, somewhat like the master Igor Stravinsky. Currents and crosscurrents arise from the orchestra whether in gentle percussion, shifting accents in the brass with timpani, or merely a restrained indefinable hum. Then comes a chattering of winds, a swoop of strings, or genteel pizzicato.

While all this goes on down below in a mildly dissonant way, three women are singing poetry in a high tessitura, more like added instruments than like voices conveying textual meaning—an unusual effect also used by Luciano Berio in the past. But the concert program dutifully printed out all the texts from Sapho, Rimbaud, Anne Carson and others, dwelling on everything from changing seasons to aphorisms to a monster apparition turning up at night.

The voices of the sopranos and mezzo came in close harmony, neatly in pitch, providing the frosting on Balch’s cake served up two years late. (Scheduled here in early 2020, it had been delayed till now by the pandemic.) The female vocal trio—Molly Netter, Alexandra Smither and mezzo Kelly Guerra—was a steadying influence on the orchestra, which went off purposefully in seeming random directions like a pet on too long a leash, to very refreshing effect.

The orchestra under Donato Cabrera went at it with gusto, though the music director admitted afterward that preparing “Illuminate” on only four rehearsals was a real challenge. Balch too took bows, seemingly mystified by the unscripted fire-brigade finale.

A fifth rehearsal might have helped the opening work, Thomas Adès’ “Three Studies from Couperin,” which the orchestra rendered rather tentatively. Adès had embellished Couperin’s three-century-old harpsichord solo pieces with modern instruments, somewhat in the vein of Leopold Stokowski “updating” Bach with a 19th-century orchestral patina.

After the firemen spent most of an hour inspecting the Lesher Center for smoke or flame, the second half resumed with French music by Debussy and Ravel. The ensemble had opened its matinee with the Ukrainian National Anthem, a vigorous march representing solidarity of Californians with Ukranians who are victims of on-going warfare.

Composer Balch, originally from the San Diego area, now teaches on the faculty of Yale University. She is the latest of the Symphony’s Young American Composers, which previously had featured Mason Bates, Kevin Puts, and Christopher Theofanidis among others.

The never-say-die orchestra will perform yet another world premiere, Viet Cuong’s “Chance of Rain” May 14-15. Presumably spared the fire alarm.

WORLD PREMIERE BY KATHERINE Balch, “Illuminate,” plus other works played by the California Symphony March 26-27, Lesher Center for the Arts, Walnut Creek. For info on the orchestra, (925) 943-7469, or go online: www.californiasymphony.org.