Julieta Bool

“The Church acknowledges Gregorian chant as specially suited to the Roman liturgy: therefore, other things being equal, it should be given pride of place in liturgical services. But other kinds of sacred music, especially polyphony, are by no means excluded from liturgical celebrations, so long as they accord with the spirit of the liturgical action.”
― Pope Paul VI, Sacrosanctum Concilium: Constitution on the Sacred Liturgy

“Regulation of the sacred liturgy depends solely on the authority of the Church, that is, on the Apostolic See and, as laws may determine, on the bishop. In virtue of power conceded by the law, the regulation of the liturgy within certain defined limits belongs also to various kinds of competent territorial bodies of bishops legitimately established. Therefore no other person, even if he be a priest, may add, remove, or change anything in the liturgy on his own authority.”
― Pope Paul VI, Sacrosanctum Concilium: Constitution on the Sacred Liturgy