36 We must also hold in honor that music which is not primarily a part of the sacred liturgy, but which by its power and purpose greatly aids religion. This music is therefore rightly called religious music. The Church has possessed such music from the beginning and it has developed happily under the Church's auspices. As experience shows, it can exercise great and salutary force and power on the souls of the faithful, both when it is used in churches during non-liturgical services and ceremonies, or when it is used outside churches at various solemnities and celebrations.
Source: Musicae Sacrae (Vatican.va)