What kinds of things are mutable in Latin Rite Catholic Liturgy?
Not everything is immutable in the Sacred Liturgy of the Roman Rite.
What are some examples of the "elements which are subject to change" and how have they done so over the years? Has this change increased or remained steady since Vatican II?
In the Holy Sacrifice of the Mass, the words of consecration are immutable as well as the matter used in the Mass. That is to say a priest priest must used bread of wheat grains and wine. We can not use rice wafers or sake for example, since that constitutes invalid matter for the act of consecration at Mass.
However, the wine itself can be red or white. I suppose the colour of the wine does not matter. In fact I believe the wine could be of any colour: rosé, orange or even black for that matter.
For there to be a valid Mass, the form of consecration ("For this is my body…" and "For this is the chalice of my Blood…") cannot ever change, but the language in which it is said may change with ecclesiastical approval.
Since Vatican II, the liturgy can be said in any language that has been approved by Rome. In the Extraordinary Form of the Mass the Mass was almost exclusively said in Latin. However exceptions were permitted:
Although Latin prevails in the West as a unified liturgical language, in the face of certain circumstances the Roman church has made exceptions to provide a language in the Liturgy more familiar to the people. It is in the ninth century among the Slavic nations that we find a departure from liturgical Latin in divine worship. A privilege was first granted to Sts. Cyril and Methodius, by Pope Hadrian II in 869, and again by Pope John VIII in 880 to use the vernacular (Slavonic) in the Liturgy.
Another example of the flexibility of which the Roman rite is capable is the privilege granted for the use of Chinese as a liturgical language. History records in the fourteenth century that the first Franciscan missionary to China, John of Monte Corvino, used the vernacular in the Liturgy.26 Pope Paul V, in a brief of June 27, 1615, granted the same privilege to Jesuit missionaries. As recently as 1949, the privilege to use the Chinese literary language in the Liturgy was granted by the Holy Office.
Still further concessions have been granted:
a) During the fourteenth century the Roman Liturgy in its Dominican variant was translated into Greek for use by the Dominican missionaries in Greece.
b) Permission had been granted to celebrate the Dominican Liturgy in the Armenian classical language in Armenia.
c) At the end of the sixteenth century missionaries of India of the Latin rite were allowed to celebrate Mass in Syriac.
d) In the seventeenth century the Discalced Carmelites were granted permission to use Arabic in their mission foundation in Persia.
e) In the seventeenth century the Theatine Clerics were granted permission to use Georgian or Armenian in their mission foundation in Georgia.
f) In the nineteenth century the Franciscans in the Holy Land were granted permission to use Arabic.
g) In 1958, an indult was granted India to use Hindi.
h) Five Latin priests in the Holy Land were granted permission to use Hebrew.
i) In 1959, the Holy See renewed Germany's privilege to use the vernacular (German) in the Epistle and Gospel after they are recited in Latin. - Liturgical Languages
Portions of the liturgy were even permitted to be celebrated in Native American vernaculars
The feast days of saints may change from time to time due to a variety of reasons. St. Dominic’s feast day for example was changed from August 4 to August 8. He had died on August 6, 1221 which is the Feast of the Transfiguration of Our Lord. On August 4, 1856 the now famous Curé d'Ars, St. Jean-Baptiste-Marie Vianney died. Due to his popularity, his Feast Day is now on August 4, while St. Dominic celebrates his on August 8. Again the Church is always growing liturgically speaking.
In the Mass of Pope St. Paul VI, the sign of peace was introduced into the liturgy and as such remains optional in this Rite.
Communion may be received kneeling or standing and on the tongue or on the hand in the New Rite. But Rome is free to reverse this freedom and impose that it should be done as in the Old Rite: kneeling and on the tongue. The liturgy is never stagnate, but is constantly developing to the needs of the Church. It is the organic development of the liturgy.
At High Masses in both Latin Rites, incense is permitted to be used, but what incense used is left to the discretion of the one in charge of the liturgy. As for myself, I prefer the Damascus Rose on the feasts of Our Lady.
The Rituale Romanum allows for some special blessing on specific feast days in both Forms of the Mass. Although somewhat more popular in bygone days they are still somewhat in vogue amongst more traditional region around the world. Unfortunately most Catholics of the Latin Rite do not even know these liturgical blessings exist.
Several different formulas now exist in the Rituale Romanum of Pope St. Paul VI, but they are an awesome way to enhance our devotion to the liturgy, tradition and sacramentals. Many of these blessings are said around the Mass, either before, during or after Mass according to the circumstances and norms layer down in the Roman Ritual.
Many more similar blessings exist which could be incorporated into our liturgical prayer life if we just look hard enough. Some are even reserved for the