Well, school has started up again, which means that in one area of many parishes the music director has little say in the quality of the liturgy.
The School Mass.
In many places, Masses are assigned to a class or grade, which means that the teacher of the class, who may or may not be a practicing Catholic, who almost certainly does not have any liturgical training, is responsible for training lectors, writing petitions, and "choosing the hymns."
Often the teacher runs forward gamely with this responsibility under the illusion that Masses can have a "theme," which specifies the appropriate songs for the Mass. Hopefully there are not too many Halloween hymns around, but in many programs undoubtedly the hip, modern, forty-seven year old Make Me a Channel of Your Peace will make a brand new splash this October.
I feel the school Mass is a huge issue in any parish beginning to reform its liturgy. In addition to the children and their teachers, all of whom are having bad liturgical instincts reinforced and your positive Sunday instincts undone, often these Masses are also attended by the most devout parishioners, often parish leaders. So the retired parish leaders and daily Communicants, the salt of the earth, but accustomed to grooving at Mass to the greatest hits of the 70s and 80s, will have all your good Sunday work undermined.
The best kind of theme--still mistaken--is the homiletic theme. This kind of thematic Mass, enshrined in some hymnals that abound in "hymns of the day," takes its cue from the readings of the day.
One of the many huge benefits of the use of the Proper texts at Mass is how they carry us out of the idea that we can master the Mass, making it small enough that anyone can fill in the blanks of a liturgy planning sheet as though it were a religious game of Mad Libs.
There is no theme. Or rather there is one theme. We cannot tame it; it should master us. We cannot confine it on our property, like a pond. But if we're willing, we can swim in the depths of its ocean, subject to its tides.
As with almost all of our liturgical tragedies, this one can be solved by focusing on the young. Train a child in the way he should go, and when he is older he will not depart from it. Let's teach the children to sing the song of the Church, and soon enough, all will be well.