Boston Children’s Chorus, 70-voices strong, burst through Isabella Stewart Gardner Museum’s Calderwood Hall Saturday with“It’s Been 15!” The program spoke as much to the ensemble’s durability as to its widespread recognition. In 2013, its founding year, BCC received the National Arts and Humanities Youth Program award from the White House.

Touting successes, though, seems secondary to wanting to get its real message out. “Boston Children’s Chorus is a creative social integration organization that unites area children ages 7-18 across differences of race, religion and socioeconomic status to discover the power of singing and transcend social barriers in a celebration of shared humanity and love of music.”

And that is just what the many on hand at Calderwood Hall experienced: an exuberant and memorable hour coming the weekend before America’s native holiday, Thanksgiving.

And just as apposite, opening the youth-filled vocal extravaganza were the words of the poet and social activist Langston Hughes, I dream a world where man, no other man will scorn. The setting, a mix of genres for both voices and piano, one fully accessible to today’s American ear,  allowed the Boston Children’s Chorus to dream in quiet tones as well as in excited climatic passages.

These devoted young voices achieve magnificence and true understanding in the centuries old composition of Renaissance master Monteverdi, Sfogava con le Stelle (Together with the stars). Dressed in jet black short-sleeved shirts and khaki trousers, most of Boston Children’s Chorus clustered on the first floor, while a row of young women sang from the second level, this to interesting, if not slightly unbalanced effect

Each of the eight choral pieces received brief introductions by one or more chorister. “One of the most difficult” to perform, we were told, was Eric Whitacre’s setting of “Leonardo Dreams of His Flying Machine.” Also, we would hear in this performance the “passion and love the singers give to it.”

Truer words could not have been spoken. The Chorus conjured just right in its vocalizing sound effects of the flying machine called for in the score. Why the setting was so long would be one of but a few reservations to surface the whole of the program.

“Will There Really Be a Morning?” followed in a fine contrast. Simple harmony, pure voices, Emily Dickinson’s words, together with contemporary or pop styled touches from the piano created an absorbing reflective mood. How could this be—so finely tuned youth to the pitch of the music and the poem!

We learned through another introduction, this, to “Home,” that more than a few of the singers in the Chorus over the years dealt in some way with depression. Mama in bed all day:/I only want to sleep./I want to sleep forever./I fall asleep with Mama, dreaming. Agitated undercurrents ran throughout an oft fast-moving patter song. Virtuosity and stamina from these choristers invited appreciation.

A member of the group introduced “The Wisdom of the Moon” as a promise there would be another day. Again, these choristers and a soloist, moving away from and back into the chorus, responded ever so exquisitely both tonally and expressively.

Polyrhythms of a sort in Haitian style energetically pronounced Men Ale-Men Vini (A little Give and Take). Here, Anthony Trecek-King, President and Artistic Director, danced out his conducting. There was plenty of action all around.

But more of that would come with the closer, “The Storm is Passing Over,” thoroughly gospel driven with choristers arms giving way to praise. Applause rang out, the crowd on its feet, and the Boston Children’s Chorus broke out with the refrain of “Halleluah” all over again with all in the hall joyously clapping in upbeats.

Still more? The answer is yes. Mingling with the crowd, the choristers personally thanked the many enthusiasts in attendance for coming.

David Patterson, Professor of Music and former Chairman of the Performing Arts Department at UMass Boston, was recipient of a Fulbright Scholar Award and the Chancellor’s Distinction in Teaching Award. He studied with Nadia Boulanger and Olivier Messiaen in Paris and holds a PhD from Harvard University. He is the author of 20 Little Piano Pieces from Around the World (G. Schirmer). www.notescape.net