It is fitting that there be a cantor or a choir director to lead and sustain the people in the singing. When in fact there is no choir, it is up to the cantor to lead the different chants, and the people take part in the way proper to them.

General Instruction on the Roman Missal, 104

Among music ministers, the cantor has come to be recognised as having a crucial role in the development of congregational singing.

Liturgical Music Today, 68