0 ENCYCLICAL OF POPE PIUS XII ON SACRED MUSIC TO OUR VENERABLE BRETHREN, THE PATRIARCHS, PRIMATES, ARCHBISHOPS, BISHIOPS, AND OTHER LOCAL ORDINARIES IN PEACE AND COMMUNION WITH THE APOSTOLIC SEE Health and Apostolic Benediction. The subject of sacred music has always been very close to Our heart. Hence it has seemed appropriate to us in this encyclical letter to give an orderly explanation of the topic and also to answer somewhat more completely several questions which have been raised and discussed during the past decades. We are doing so in order that this noble and distinguished art may contribute more every day to greater splendor in the celebration of divine worship and to the more effective nourishment of spiritual life among the faithful.
Source: Musicae Sacrae (Vatican.va)