The Liber (as it is commonly called) is first and foremost a practical combination of the various official liturgical-musical books of the Roman Rite (e.g., Kyriale, Graduale Romanum, Cantorinus, Officium Hebdomodae Sanctae Instauratus) used for both chanting the various parts of the Divine Office and the Holy Sacrifice of the Mass. It also contains a wealth of ancient Latin hymns, ad libitum Kyriale modes, litanies and even the Ordo Missae (the Ordinary, Prefaces and Canon of the Mass) allowing it to be used in place of a daily missal during Mass. The Liber further explains the names of the various components of Gregorian chant, the method for properly rendering it according to the "Solesmes method" (ordered by the Holy See to be followed by all who use the Roman Rite), how to chant the Lessons, Epistles and Gospels, a universal 1961 Roman calendar, a section on general rubrics for applying the calendar and classification system (according to the 1960 reform) in addition featuring important particular rubrical notes as necessary (e.g., for the ceremonies of Ash Wednesday), a general index as well as alphabetical indexes for the various parts of the propers, antiphons, psalms (even a numerical index for these), canticles, and hymns, and much more! |