"This minimum repertoire of Gregorian chant has been prepared with that purpose in mind: to make it easier for Christians to achieve unity and spiritual harmony with their brothers and with the living traditions of the past. Hence it is that those who are trying to improve the quality of congregational singing cannot refuse to Gregorian chant the place which is due to it." - Pope St. Paul VI, 1974

https://www.churchmusicassociation.org/wp-content/uploads/2024/03/Jubilate-Deo.pdf