As always, I note the kind contribution of Richard Chonak who translated the Latin original of the second edition (1988). Let’s look at the Ordinary music of the Introductory Rites:
2. The acclamations Kyrie, eleison can be distributed among two or three cantors or choirs, if
appropriate. Each acclamation is to be sung in a two-fold manner, yet a greater number is not excluded, especially considering reasons of musical art, as indicated below, n. 491.1When the Kyrie is sung as part of the penitential act, brief tropes are placed before the
individual acclamations.
You might expect my criticism of this section lies along the principle that the assembly should be singing a good portion of a penitential act. After all, it is for the benefit of confessing one’s own need for mercy, not allowing the choir to serve a quasi-priestly function.
The relevant section cited above is reproduced here:
1. For chants in the Order of Mass the Kyriale Romanum and Kyriale simplex are to be It is permitted for the selection of chants to depend first of all on the ability or capacity of the singers; more ornate melodies are preferred in more solemn celebrations.
This music is at the service of a sense of progressive solemnity. Still, I would be hesitant about removing the people’s voices from this part of the Ordinary on those solemn celebrations, where the options for ritual are many and varied.
Note that the three-plus-three-plus-three format should be retained to respect the composition of a piece:
2. Pertaining to the chant of the Kyrie, when nine invocations are notated fully, the musical form requires that they be sung in their entirety. In contrast, when one melody is to be repeated for the first invocations of Kyrie, this invocation is only sung twice. Similarly for the following invocations Christe and Kyrie (for example, Kyrie V). When the final Kyrie is written with a distinct melody (e.g., Kyrie I), the Kyrie preceding it is only sung once. In this way the general rule of repeating each invocation once is preserved.
3. When the Kyrie is employed as a response to some invocation in the penitential act, the melody of this response should be chosen either from Kyrie XVI or XVIII of the Kyriale Romanum, or a melody from the Kyriale Simplex.
An important liturgical reminder, namely that the Kyrie Eleison is not an automatic part of the Sunday Eucharist:
4. When the rite of blessing and sprinkling holy water is done in place of the penitential act in Sunday Masses, the antiphon Asperges me is sung, or in Paschaltide, Vidi aquam.
If anyone has comments on the particular repertoire of the Kyriale, happy to hear it. You can link in the comboxes, if you’re careful. Other thoughts?
Catholic Sensibility 
“After all, it is for the benefit of confessing one’s own need for mercy, not allowing the choir to serve a quasi-priestly function.”
While I agree that ‘active participation’ is the rule of the day, I would argue that one must be careful not to necessarily ascribe the meaning of exterior activity to it. We must remember that the mindset of the Church is that we are collectively a body each with their own duties and responsibilities (which is not to say that there can’t be some cross-over). For five hundred years prior to the Second Vatican Council, the people had almost no part in the Liturgy, and although this was perhaps not the most useful application of theology, it was however still valid. It is a very fine balancing point between inclusion and exclusion, one for which I’m not sure we have yet developed a good theology.
I think that practitioners of the spiritual life might give guidance to the theology. I like the traditional term “practicing Catholic.” My sense of it is that the Christian life is not something absorbed intellectually or even artistically, but something that due to our flawed human nature, must be practiced before it is made perfect.
As a parent, mentor, and sometimes-teacher, I find that one integrates–learns if you will–by doing. If we are more than students–scholae, if you will–we are apprentices in the way of Christ. Apprentices work and do alongside the master. In that regard, exterior practice reinforces an interior discipline. I agree that exterior participation is no guarantee that a person “gets” the Christian life. But even attentive listening doesn’t guarantee it either–in fact, it can be easier to mask distractions, even unholy distractions, when one’s silent assent is unencumbered by the rightful demands of liturgy.