On paper, the theme to last weekend’s Monadnock Chorus concert was Americana, but beneath the sometimes silly, sometimes patriotic, always beautiful performance was another underlying theme: the American ideal of self-reliance.

Often the chorus performs with a large orchestra. Last spring, it included 43 instruments. This year, the chorus was accompanied by only three instruments, piano, drums and a stand-up bass. And as often as not, these were not used at all.

Early in the performance, the chorus performed Three Choral Prayers, a piece by Dublin composer Craig Sandford. The whole piece was performed a cappella. The bare chorus had an exquisite sound that easily could have been lost behind the veil of musical instruments. It was a big sound, yet dynamic. As each of the three prayers ended in turn with a harmonized “amen,” one could feel the power of their voices lingering in the air.

The choice to include Sandford’s piece spoke to another aspect of the chorus’s self-reliance — utilizing local composers. Too often, “local art” has a connotation of being inferior to the great artists who have made it in places like New York. The reality is that local artists are the best able to speak to their own neighbors, intimately aware of what life is like in our corner of the world.

Sandford was one of several composers from the area, including Steve Murray of western Massachusetts, who arranged the closing number and was in the audience, Edward MacDowell, whose wife ran the MacDowell Colony in his name for decades, Joel Hayden, who was the first conductor for the Monadnock Chorus and Zeke Hecker of Guilford, Vt., who composed one of the highlights of the concert.

Hecker’s piece, “A Morning Star,” set to music passages taken from Thoreau’s “Walden.”

Containing four movements, the composition was among the most memorable of the concert. Light and airy, the upper voices sang “Time is but a stream I go a-fishing in...,” then followed by the lower voices, who repeat it as if a round. Floating high and in the air, those upper voices sang “Castles, castles, castles...” as the lower voices literally built a musical foundation under them, alluding to the famous Thoreau quote about building castles in the air.

The third part of the movement, The Earth’s Eye, still haunts me with its distinct rhythm, declaring a lake landscape’s “most beautiful and expressive feature.” The movement ends with the declaration, “A lake!”

The last movement, which shares a title with the whole piece, included rich tones, fading voices and a lonely piano. Listening to it had the wonderful finality of a sunrise after an all-nighter. “The sun is but a morning star.”

All through was the excitement of hearing a piece never before heard, and something that sounded like real music, something that could last.

The second half of the concert included a varied program that explored America in different ways, and none of them less legitimate than the first.

One piece with special significance for conductor Jim Sharrock was “Shenandoah.” Sharrock is from the West Virginia landscape the song describes. Featuring his wife, Cheryl, and daughter, Miriam, on four-hand piano, Sharrock shared himself and his family with his chorus and his audience.

The singers sang with power and emotion as if the song had been about our Monadnock, and in a way it was. Our country, coast to coast, holds a personal connection to each one of us, whether that connection is through a lone mountain or a winding river. We all own that connection, and we all sing the same song.

Oh, and the chorus also sung the best rendition of “O Susanna” I’ve ever heard. Some of you will not believe me, but trust me — it was beautiful music.

Late in the program, the Peterborough Children’s Choir, which will perform May 8, joined the chorus for two songs on its own — “When Lilacs Bloom’d” from a poem by Walt Whitman and “Can You Hear” from Sounds of a Better World — and then for the concert’s patriotic finale. The Children’s Choir voices sang rich harmonies with complicated call and response. In some ways they were the stars of the show.

Between songs Sunday afternoon, Sharrock announced that the Monadnock Chorus is a semi-finalist for Choral Performance with The American Prize. For more information, visit www.theamerican prize.org.

As for Sharrock himself, at the end of his first season as conductor he has shown himself to be more than capable and creative with close-by treasures. I’m looking forward to seeing what he has in store for us next time.