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Far from having the power to change the Canon of the Mass, the Congregation is supposed to make sure it is "diligently observed." No one, after Trent and Quo Primum, could change the Canon of the Mass.


Catholic Encyclopedia
https://www.newadvent.org/cathen/03255c.htm

Council of Trent Session VII
http://www.thecounciloftrent.com/ch7.htm

CANON XIII.-If any one saith, that the received and approved rites of the Catholic Church, wont to be used in the solemn administration of the sacraments, may be contemned, or without sin be omitted at pleasure by the ministers, or be changed, by every pastor of the churches, into other new ones; let him be anathema.


Council of Trent Session XXII
http://www.thecounciloftrent.com/ch22.htm

CHAPTER IV: On the Canon of the Mass. And whereas it beseemeth, that holy things be administered in a holy manner, and of all holy things this sacrifice is the most holy; to the end that it might be worthily and reverently offered and received, the Catholic Church instituted, many years ago, the sacred Canon, so pure from every error, that nothing is contained therein which does not in the highest degree savour of a certain holiness and piety, and raise up unto God the minds of those that offer. For it is composed, out of the very words of the Lord, the traditions of the apostles, and the pious institutions also of holy pontiffs.

CANON VI.--If any one saith, that the canon of the mass contains errors, and is therefore to be abrogated; let him be anathema.


1917 Canon Law

Canon 253 (NA) Cross-Ref.: 1917 CIC 1999

§ 1. The Congregation for Sacred Rites has authority to see and establish all those things that
proximately involve the sacred rites and ceremonies of the Latin Church, but not which refer to
sacred rites in the wide sense, things like the right of precedence and others of this sort, which are
treated either in the judicial order or in the disciplinary line.
§ 2. It is for it especially to be vigilant that the sacred rites and ceremonies are diligently
observed in celebrating the Sacred [Synax], in the administration of Sacraments, in conducting
divine offices, and in all those things that respect cult in the Latin Church; [it can] grant opportune
dispensations; it can give out insignia and privileges of honor whether personal or for a time,
whether to places or perpetually, in matters affecting sacred rites and ceremonies, and shall take
care lest these fall into abuse.
§ 3. Finally all those things that pertain to the beatification and canonization of the Servants of
God or to sacred relics in any way are referred to it.

CANON XIII.-If any one saith, that the received and approved rites of the Catholic Church, wont to be used in the solemn administration of the sacraments, may be contemned, or without sin be omitted at pleasure by the ministers, or be changed, by every pastor of the churches, into other new ones; let him be anathema.

It follows that, even according to the mind of the Council of Florence itself, the traditio instrumentorum is not required for the substance and validity of this Sacrament by the will of Our Lord Jesus Christ Himself. If it was at one time necessary even for validity by the will and command of the Church, every one knows that the Church has the power to change and abrogate what she herself has established.


(Pope Pius XII, Apostolic Constitution Sacramentum Ordinis, n. 3)

Quoted here - Did the Council of Florence Teach Error? A Response to Athanasius Schneider’s Attempt to Save Vatican II – Novus Ordo Watch

50. The sacred liturgy does, in fact, include divine as well as human elements. The former, instituted as they have been by God, cannot be changed in any way by men. But the human components admit of various modifications, as the needs of the age, circuмstance and the good of souls may require, and as the ecclesiastical hierarchy, under guidance of the Holy Spirit, may have authorized. This will explain the marvelous variety of Eastern and Western rites. Here is the reason for the gradual addition, through successive development, of particular religious customs and practices of piety only faintly discernible in earlier times. Hence likewise it happens from time to time that certain devotions long since forgotten are revived and practiced anew. All these developments attest the abiding life of the immaculate Spouse of Jesus Christ through these many centuries. They are the sacred language she uses, as the ages run their course, to profess to her divine Spouse her own faith along with that of the nations committed to her charge, and her own unfailing love. They furnish proof, besides, of the wisdom of the teaching method she employs to arouse and nourish constantly the "Christian instinct."


51. Several causes, really have been instrumental in the progress and development of the sacred liturgy during the long and glorious life of the Church.

52. Thus, for example, as Catholic doctrine on the Incarnate Word of God, the eucharistic sacrament and sacrifice, and Mary the Virgin Mother of God came to be determined with greater certitude and clarity, new ritual forms were introduced through which the acts of the liturgy proceeded to reproduce this brighter light issuing from the decrees of the teaching authority of the Church, and to reflect it, in a sense so that it might reach the minds and hearts of Christ's people more readily.

53. The subsequent advances in ecclesiastical discipline for the administering of the sacraments, that of penance for example; the institution and later suppression of the catechumenate; and again, the practice of eucharistic communion under a single species, adopted in the Latin Church; these developments were assuredly responsible in no little measure for the modification of the ancient ritual in the course of time, and for the gradual introduction of new rites considered more in accord with prevailing discipline in these matters.

54. Just as notable a contribution to this progressive transformation was made by devotional trends and practices not directly related to the sacred liturgy, which began to appear, by God's wonderful design, in later periods, and grew to be so popular. We may instance the spread and ever mounting ardor of devotion to the Blessed Eucharist, devotion to the most bitter passion of our Redeemer, devotion to the most Sacred Heart of Jesus, to the Virgin Mother of God and to her most chaste spouse.

55. Other manifestations of piety have also played their circuмstantial part in this same liturgical development. Among them may be cited the public pilgrimages to the tombs of the martyrs prompted by motives of devotion, the special periods of fasting instituted for the same reason, and lastly, in this gracious city of Rome, the penitential recitation of the litanies during the "station" processions, in which even the Sovereign Pontiff frequently joined.

56. It is likewise easy to understand that the progress of the fine arts, those of architecture, painting and music above all, has exerted considerable influence on the choice and disposition of the various external features of the sacred liturgy.

57. The Church has further used her right of control over liturgical observance to protect the purity of divine worship against abuse from dangerous and imprudent innovations introduced by private individuals and particular churches. Thus it came about - during the 16th century, when usages and customs of this sort had become increasingly prevalent and exaggerated, and when private initiative in matters liturgical threatened to compromise the integrity of faith and devotion, to the great advantage of heretics and further spread of their errors - that in the year 1588, Our predecessor Sixtus V of immortal memory established the Sacred Congregation of Rites, charged with the defense of the legitimate rites of the Church and with the prohibition of any spurious innovation.[48] This body fulfills even today the official function of supervision and legislation with regard to all matters touching the sacred liturgy.[49]

58. It follows from this that the Sovereign Pontiff alone enjoys the right to recognize and establish any practice touching the worship of God, to introduce and approve new rites, as also to modify those he judges to require modification.[50] Bishops, for their part, have the right and duty carefully to watch over the exact observance of the prescriptions of the sacred canons respecting divine worship.[51] Private individuals, therefore, even though they be clerics, may not be left to decide for themselves in these holy and venerable matters, involving as they do the religious life of Christian society along with the exercise of the priesthood of Jesus Christ and worship of God; concerned as they are with the honor due to the Blessed Trinity, the Word Incarnate and His august mother and the other saints, and with the salvation of souls as well. For the same reason no private person has any authority to regulate external practices of this kind, which are intimately bound up with Church discipline and with the order, unity and concord of the Mystical Body and frequently even with the integrity of Catholic faith itself.