This is such an exciting and thrilling performance! The small changes from the Roman version are intriguing. Listening to this really makes me wonder if there are differences in conventions between parish and monastic practice. There is something about the pacing here that suggests a certain timelessness.
Take note of the sheer variety here, the differences in the way each chant is rendered. This is just so masterful. The structure is super tight, highly ordered, very practiced, and yet...the singing has a wild spontaneity to it that sometimes suggests total elation.