Thank you. I had a chance to go through it, and while an expert might be able to add or correct something from what I see, it appears that the one chant that they are doing is the alleluia verse of the common of holy Popes ( or sts Peter and paul ) —. The rest seems to be overwhelmingly from Easter, except that the litany of the Saints has the response, “come to his assistance.” .It uses the same verb as opens each hour in the Liturgy of the Hours . The mass ordinary is Missa de Angelis. There is chant throughout, but primarily in the form of responses and prayers. Anyone who sees anything else please feel free to add.

Thanks. I’ll put that on the study list/- which I do have.