Thanks for including that. I can't believe I forgot to put it here in the first place. You should have mentioned that (a) all the books are in Greek, and (b) according to the site compiler, all the books are from Byzantine Music composers & theorists who are in the school of "Traditional Patriarchal."
"O Cross of Christ, all-holy, thrice-blessed, and life-giving, instrument of the mystical rites of Zion, the holy Altar for the service of our Great Archpriest, the blessing - the weapon - the strength of priests, our pride, our consolation, the light in our hearts, our mind, and our steps"
Met. Meletios of Nikopolis & Preveza, from his ordination.