The All Saints' Choir of Men and Boys (also known as the Ashmont Boy Choir), is modeled on the English Cathedral choral tradition and assists in leading worship at the 10:00 am Solemn High Mass at All Saints' on Sundays during the school year. The Choir performs the finest sacred music from Gregorian chant to the works of living composers, singing a full mass setting, a psalm setting, and an anthem or motet every Sunday.

In addition, the Choir seeks to enrich the life of the greater Boston community through its concerts, collaborations with other choirs, and recordings. Ethnic and racial diversity is a hallmark of the Choir, and this highly-valued diversity mirrors the demographic makeup of the parish and of its Dorchester neighborhood.

The boys and teens—aged 7 to 18 and mostly coming from the neighborhoods and communities surrounding Dorchester—are joined by professional and volunteer adult singers from the greater Boston area.

A partnership with the Harvard Glee Club puts the boys in regular contact with young Harvard men through the Archibald T. Davison Fellowship. ("Doc" Davison was Organist at All Saints' in the early 20th century until he left to become University Organist at Harvard, eventually becoming the first formal director of the Glee Club.) The Davison Fellow attends weekly rehearsals, assisting with musical training and providing homework assistance and other mentoring support, and also sings with the Choir during services and performances.

The Choir provides the boys a safe place in which to make new friends, experience the uplifting power of great music, discover the value of teamwork and responsibility, and learn musical and life skills that will last them a lifetime.