Psallite from The Liturgical Press would go, I believe, under option 3.
191. In selecting a Communion song suitable for the Eucharistic banquet in which God’s blessings are bestowed so abundantly, one should look for texts that have themes of joy, wonder, unity, gratitude, and praise. Following ancient Roman liturgical tradition, the Communion song might reflect themes of the Gospel reading of the day. It is also appropriate to select a Communion processional song that reflects the liturgical action, i.e., eating and drinking the Body and Blood of Christ. [my emphasis]
Also under option 3 would go other Graduale antiphons/psalms from the same season; the rubrics in the Ordo cantus Missæ do allow, as Ruff has pointed out, for the use of, say, any Lenten introit at any Lenten Mass. I personally don't think this was such a great idea, and they would have done better to designate a handful of seasonal propers from the Graduale Romanum--similar to how they did designate 7 or so communions for use "ad libitum".
Psallite's communion texts are from the Graduale Romanum wherever the Graduale text reflects the deepest theology of the communion song of the ancient Sunday gradual: the gospel communion (because communion is the fruit of the proclaimed word, especially the gospel, the communion song ideally "quotes" the proclaimed word, especially the gospel).
Why are they singing accompanied music without accompaniment? Singing a popular song without piano or guitar does not make it chant.
These examples lack the musical integrity to stand on their own and would be rejected by any freshman theory teacher as incomplete.
I have looked at and listened to the Psallite samples that are provided on the site. I simply don't see the connection between the texts, which seem to have been written as "lyrics" more than prose, and those of the Gradual.
Where I see this concept breaking down is:
Aren’t the psalmic communions actually older?
Most of the Advent and Christmas communions are from the Old Testament, yet ISTM they stand on an equal footing with the idea of quoting the day’s gospel.
To participate in the discussions on Catholic church music, sign in or register as a forum member, The forum is a project of the Church Music Association of America.