For his last concert after ten years as music director of the Marin Symphony, Gary Sheldon conducted an exciting and in-depth all Aaron Copland program, Nov. 19 and 21.

Both the orchestra and the audience showed how far they have grown in the time of Sheldon's stewardship, during which he has introduced a total of 60 new works. The music on the program was a selection of the known and the unknown.

Three lesser-known Copland works comprised the first half, with his Symphony No. 3, with its famous "Fanfare for the Common Man" in the second half. The program was a well orchestrated study of the variety in Copland's music.

A lively "El Salon Mexico" showed Copland at his most folkloric, with famous Mexican tunes pastiched throughout. The piece, written in 1937, was named after a dance hall in Mexico City that Copland frequented. The clarinet interlude with its syncopated rhythm gave the piece a jazzy lilt, like so much of his work, and the brass juxtaposed with the violins made this a fitting piece to start the concert, as it contained the seeds of most of Copland's later works.

The next two pieces featured soloists from the orchestra. "Quiet City" was incidental music for a play bearing the same name by Irwin Shaw. in it the night sounds of the city were evoked by the deeply resonant and confident English horn of Laura Reynolds Chrisp. Answering her was the brilliant trumpet of Carole Klein that sounded so rich in the Marin Center Veterans Auditorium.

"Caprice for Violin and Orchestra" a short, (8-minute), difficult work, was played by the talented Peggy Brady, the symphony's principal violin II. Her energy and musicianship for this virtuosic piece shows the strength of the symphony orchestra that has such fine members.

After the intermission the symphony played the challenging Symphony No. 3. The symphony contains all of Copland's ideas and incorporates one of his best-known pieces, "Fanfare for the Common Man." Copland wrote "Fanfare" in '42, the beginning of World War II, and he fully intended it to ring with frank patriotism and haunting heroism. The orchestra did justice to this stirring interlude, as they did with the entire concert.

Copland would have been 100 this year if he had lived. He, along with Samuel Barber and Leonard Bernstein, may be considered the most important American composers of the 20th century. Even though Copland studied in Paris with Nadia Boulanger, he remained essentially an Americanist.

One of the greatest musicial thrills that I have ever experienced was seeing him conduct "Appalachian Spring" in Ann Arbor, Mich., in the late '50s. His lower arms and hands seemed disjointed from the rest of his body as he moved them up and down in a most peculiar way. He was an evangelist for American music, as he lectured on it and introduced it to a Euro-centric audience bred on Bach, Beethoven and Brahms. Little did he know that almost half a century later, his music would make up the entire program in faraway Marin County, Calif.

Thanks to Gary Sheldon, who has insisted on moving the audience along with these more unusual selections, it looked like, from the night's concert, that both orchestra and audience seemed to enjoy the experience. The entire audience gave Sheldon a standing ovation in this his last concert. And the orchestra surprised him with a brief excerpt from "Where in the World is Carmen Sandiego," the popular yearly children's concert developed during Sheldon's tenure.

After 10 years, during which he also enriched the programs of the Marin Symphony Youth Orchestra and its Outreach Program, Sheldon will now take up the baton at the Festival at Sandpoint, Idaho. He continues as music director of the Lancaster Festival in Ohio.