Gregorian Chant is the model, the quintessential ideal of song in the Roman Rite. It has always been so from time immemorial. Therefore preference should be given to Gregorian Latin Propers above all else. The number of musicians who have been persuaded by this argument seems to be increasing ― there are more churches and cathedrals where Gregorian Introits, Offertory chants and Communion chants from the Graduale Romanum are being regularly used, though they are still in a tiny minority.
Support from the documents:
Tra le sollecitudini (1903)
3. These qualities are to be found, in the highest degree, in Gregorian Chant, which is, consequently the Chant proper to the Roman Church, the only chant she has inherited from the ancient fathers, which she has jealously guarded for centuries in her liturgical codices, which she directly proposes to the faithful as her own, which she prescribes exclusively for some parts of the liturgy, and which the most recent studies have so happily restored to their integrity and purity.
On these grounds Gregorian Chant has always been regarded as the supreme model for sacred music, so that it is fully legitimate to lay down the following rule: the more closely a composition for church approaches in its movement, inspiration and savor the Gregorian form, the more sacred and liturgical it becomes; and the more out of harmony it is with that supreme model, the less worthy it is of the temple.
Sacrosanctum Concilium (1963)
116. 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.
Musicam Sacram (1967)
50. In sung liturgical services celebrated in Latin:
(a) Gregorian chant, as proper to the Roman liturgy, should be given pride of place, other things being equal. Its melodies, contained in the “typical” editions, should be used, to the extent that this is possible.
(b) “It is also desirable that an edition be prepared containing simpler melodies, for use in smaller churches.”
GIRM (1969 and succeeding versions)
41. The main place should be given, all things being equal, to Gregorian chant, as being proper to the Roman Liturgy.
John Paul II Chirograph on Sacred Music (2003)
7. Among the musical expressions that correspond best with the qualities demanded by the notion of sacred music, especially liturgical music, Gregorian chant has a special place. The Second Vatican Council recognized that “being specially suited to the Roman Liturgy” it should be given, other things being equal, pride of place in liturgical services sung in Latin. St Pius X pointed out that the Church had “inherited it from the Fathers of the Church”, that she has “jealously guarded [it] for centuries in her liturgical codices” and still “proposes it to the faithful” as her own, considering it “the supreme model of sacred music”. Thus, Gregorian chant continues also today to be an element of unity in the Roman Liturgy.
Sing to the Lord (2007)
72. “The Church recognizes Gregorian chant as being specially suited to the Roman
Liturgy. Therefore, other things being equal, it should be given pride of place in liturgical
services.” Gregorian chant is uniquely the Church’s own music. Chant is a living connection
with our forebears in the faith, the traditional music of the Roman rite, a sign of communion with the universal Church, a bond of unity across cultures, a means for diverse communities to
participate together in song, and a summons to contemplative participation in the Liturgy.
THE OTHER THEORY:
The Church clearly envisages that Gregorian chant is not the only possibility, and not necessarily even the preferred option. It is quite clear that pastoral considerations have to take priority.
Other possibilities enunciated in the documents:
114. The treasure of sacred music is to be preserved and fostered with great care. Choirs must be diligently promoted, especially in cathedral churches; but bishops and other pastors of souls must be at pains to ensure that, whenever the sacred action is to be celebrated with song, the whole body of the faithful may be able to contribute that active participation which is rightly theirs, as laid down in Art. 28 and 30. [my emphasis]
116. 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, as laid down in Art. 30.
118. Religious singing by the people is to be intelligently fostered so that in devotions and sacred exercises, as also during liturgical services, the voices of the faithful may ring out according to the norms and requirements of the rubrics.
119. In certain parts of the world, especially mission lands, there are peoples who have their own musical traditions, and these play a great part in their religious and social life. For this reason due importance is to be attached to their music, and a suitable place is to be given to it, not only in forming their attitude toward religion, but also in adapting worship to their native genius, as indicated in Art. 39 and 40.
Therefore, when missionaries are being given training in music, every effort should be made to see that they become competent in promoting the traditional music of these peoples, both in schools and in sacred services, as far as may be practicable.
9. In selecting the kind of sacred music to be used, whether it be for the choir or for the people, the capacities of those who are to sing the music must be taken into account. No kind of sacred music is prohibited from liturgical actions by the Church as long as it corresponds to the spirit of the liturgical celebration itself and the nature of its individual parts, and does not hinder the active participation of the people.
48. Where the vernacular has been introduced into the celebration of Mass, the local Ordinaries will judge whether it may be opportune to preserve one or more Masses celebrated in Latin—especially sung Masses (Missae in cantu)—in certain churches, above all in large cities, where many come together with faithful of different languages.
51. Pastors of souls, having taken into consideration pastoral usefulness and the character of their own language, should see whether parts of the heritage of sacred music, written in previous centuries for Latin texts, could also be conveniently used, not only in liturgical celebrations in Latin but also in those performed in the vernacular. There is nothing to prevent different parts in one and the same celebration being sung in different languages.
41. Other kinds of sacred music, in particular polyphony, are in no way excluded, provided that they correspond to the spirit of the liturgical action and that they foster the participation of all the faithful.
John Paul II Chirograph
7. Like St Pius X, the Second Vatican Council also recognized that “other kinds of sacred music, especially polyphony, are by no means excluded from liturgical celebrations”. It is therefore necessary to pay special attention to the new musical expressions to ascertain whether they too can express the inexhaustible riches of the Mystery proposed in the Liturgy and thereby encourage the active participation of the faithful in celebrations.
12. With regard to compositions of liturgical music, I make my own the “general rule” that St Pius X formulated in these words: “The more closely a composition for church approaches in its movement, inspiration and savour the Gregorian melodic form, the more sacred and liturgical it becomes; and the more out of harmony it is with that supreme model, the less worthy it is of the temple”. It is not, of course, a question of imitating Gregorian chant but rather of ensuring that new compositions are imbued with the same spirit that inspired and little by little came to shape it. Only an artist who is profoundly steeped in the sensus Ecclesiae can attempt to perceive and express in melody the truth of the Mystery that is celebrated in the Liturgy.
Sing to the Lord
73. The “pride of place” given to Gregorian chant by the Second Vatican Council is modified by the important phrase “other things being equal.” These “other things” are the important liturgical and pastoral concerns facing every bishop, pastor, and liturgical musician. In considering the use of the treasures of chant, pastors and liturgical musicians should take care that the congregation is able to participate in the Liturgy with song. They should be sensitive to the cultural and spiritual milieu of their communities, in order to build up the Church in unity and peace.
Has in fact Gregorian chant been the primary model for song in the Roman Rite at any time in the past 600 years?
Would Tra le Sollecitudini have said the following if Gregorian Chant were “in possession” ?
3. The ancient traditional Gregorian Chant must, therefore, in a large measure be restored to the functions of public worship, and the fact must be accepted by all that an ecclesiastical function loses none of its solemnity when accompanied by this music alone.
Special efforts are to be made to restore the use of the Gregorian Chant by the people, so that the faithful may again take a more active part in the ecclesiastical offices, as was the case in ancient times.
Would Sacrosanctum Concilium have said this if everything in the garden was rosy?
117. The typical edition of the books of Gregorian chant is to be completed; and a more critical edition is to be prepared of those books already published since the restoration by St Pius X.
It is desirable also that an edition be prepared containing simpler melodies, for use in small churches.
The crux question: have the Gregorian Chant Propers actually been the norm in recent church history?
A few examples, all from the Roman Rite:
The so-called Ratisbon edition of the chants from the 16th century provided a bastardized version of Gregorian chants, and was commonly used all over Europe until the Solesmes monks produced their new editions in the late 19th-early 20th centuries. Ratisbon was not the earliest manifestation of non-Gregorian chants in the liturgy, which goes back as far as Metz in the 9th century. Other non-standard versions have abounded in different countries, for example the German-speaking nations and those of Eastern Europe.
From the 16th century onwards, polyphonic and other settings were regularly used to substitute for the Chant. Initially fauxbourdon settings were sung in alternation with the Chant, a practice perpetuated in the French “Organ Mass”, etc; but increasingly the harmonized settings came to be used exclusively. By the 18th and 19th century, the musical standard of what was being used instead of the Chant had become very low, rivalling the worst of what could be found in secular theatres. This phenomenon is what gave rise to the movement to restore Gregorian Chant to its proper place, resulting in the foundation of Gregorian societies on both sides of the Atlantic. Their work, however, has been largely in vain, affecting only a minority of parishes.
Late 19th-century and 20th century hymn books on both sides of the Atlantic contain alternatives to the Chant in great number, ranging from simple polyphonic pieces to fauxbourdon settings. Some composers even produced volumes of alternative music (“chanting tones”) for use by choirs who simply could not manage the Chant itself, and these proved very popular.
The German Singmesse from the 18th century onwards and the Betsingmesse in the 20th substituted vernacular hymn and chorale singing for the Chant.
Following the Council, it is scarcely necessary to point out, hymn singing became the first norm to accompany the Church’s rites, followed by a profusion of other styles of music, some ecclesiastical in tone, others more secular.
In most of these examples except the vernacular ones, the texts of the antiphons themselves have generally remained as provided by the liturgical books. It is the music that clothes these texts which has diverged radically from the original Gregorian Chant.
The fact of the matter is that Gregorian Chant has not, since the time of the Reformation if not even earlier, been used as a normal basis for the singing of the Propers, so in this sense is it actually possible to point to it as “always having been in pride of place”, as postconciliar proponents of Gregorian Latin Propers are wont to do? My thesis is that they/we are trying to promote as the norm something which in practice never was the norm during the past 600 years and more. This is either antiquarianism or just plain artificial. Furthermore, we now have a largely vernacular and participatory liturgy which is very different from the largely passive Latin liturgy which preceded it. In such a context, I believe making use of our great Gregorian Chant heritage requires much more subtlety and nuance than simply depositing dollops of Chant into the appropriate liturgical slots and assuming that this will do the trick.