I do like that "spinal" bookset graphic. My RV&R is related to the "a novel" thing. I just saw this at Kobo.
Apparently the plot involves music, so the title is likely a reference to the Requiem Mass. If you're aiming for people who get the reference, they don't need the translation - they may start humming/singing the line as I did. If you're aiming for people who DON'T get the reference, why bother with the Latin at all?