People approaching the Windsor Green bandstand Oct. 3 for the Sonoma County Philharmonic’s season opening concert had some cause for concern. After 18 months of silence would the all-volunteer orchestra have enough musicians for a big movie music program? After all, performers can move, retire, or bail from the arduous work that goes into playing with an orchestra.

Worries were unfounded, as conductor Norman Gamboa led a strong contingent of 47 players under a warm mid-day sun with 400 seemingly happy listeners enjoying picnics on the grass to compliment the semi-familiar music taken from recent movies.

Most of the performers were playing under popup tents, but the brass sections and Mr. Gamboa himself labored without cover, and even the solo harp had shade. Mr. Gamboa led an hour-long transversal of themes from movies such as Spiderman, Batman, Superman, Wonder Woman and music that was unknown to me. I don’t think there was anything from Harry Potter or Lord of the Rings.

The impact of the often lively music was sharply reduced by the lack of amplification, as the Philharmonic was unable to access the Green’s sound system, the large elevated loudspeakers conspicuously in place for a later afternoon pop concert.

The season continues Nov. 13 and 14 in the Jackson Theater with Strauss, Barber’s Knoxville, Summer of 1915, and Beethoven’s Symphony No. 4. Morgan Harrington is the soprano soloist in the Barber.