The Adult Choir sings at two Masses a month:
Saturday Vigil Mass 5:00 pm at St. Theresa, the Little Flower Church in Harvard and the 10:45 am Sunday Mass at St. Francis Xavier Church in Bolton.

A blend of traditional hymns, contemporary songs, and some Latin is used at all Masses throughout the year.

Holy Trinity Parish boasts of a cantor ministry of 8 adult cantors.

Cantors minister at Masses and special occasions on an average of twice a month. They, like the adult choir, travel between the two churches but cover all of  the parish Masses on a weekend.

This group of spirited singers and instrumentalists specializes in contemporary music in a variety of styles. Members are from both towns. Singers high school age and up are welcome. The contemporary group leads the music at both sites usually twice a month.

The Festival Choir sings on special occasions: 
Christmas Eve, Palm Sunday, the Sacred Triduum, Easter Sunday, feast days, holy days, confirmations, sung evening prayer services, and Lenten services.  
The adult choir forms the base of the Festival Choir, but they are joined by members of the Contemporary Group and parishioners who cannot make a weekly choir rehearsal commitment and wish to sing only on special occasions. 

The Resurrection Choir is composed of parishioners who are available on weekday or Saturday mornings, to minister to those who have lost loved ones.
This choir helps bereaved family members sing of God's mercy and faithfulness. 
Members warm up in the church 1/2 hour before the funeral.