The Liber Usualis Introduction and Rubrics in English Edited by the Benedictines of Solesmes Tournai: Desclee & Co. 1952. Plate Nº 801 Hardcover Condition: Good The Liber Usualis (pronounced Lee-behr Oos-oo-ah-lees and Latin for The Book of Common Use) is usually associated with the Gregorian chant propers sung at Mass, but its usefulness doesn't end there! 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.