I enjoyed looking through St. Basil 1906 as a window to a time. Several notable things. One is that most of the hymns are devotional and not intended for Mass. Benediction, Vespers, and days of celebration for special saints. There are some hymns for low Mass, but mostly for BVM. There are total of 200. When it comes to Mass music, there is little or no chant at all. The Missa de Angelis is here but nothing else. Other sung parts of the Mass (Asperges, Requiem, etc.) are in easy choral settings. Chant is a memory here, a vague archtype. Accompaniment seems ubiquitous. I don't know how the propers were sung in these days. Psalm tones? The old Ratisbon Gradual? I don't know. It seems like an unstable situation to me.