This collection provides English translations for the Propers of the Mass—those portions of the Roman Catholic Mass which change from day to day throughout the Liturgical Year. Since the Middle Ages, these texts were set to music in the form of chant, and later as motets, and sung during the service of the Mass. Many of these musical works are the standard literature for choirs today and are regularly performed in concert and worship settings. New settings of Mass propers continue to be written by major contemporary composers. Because these settings of Latin texts are often published without English translations, this collection of more than 900 propers is a valuable reference for choral directors and church musicians and is the most comprehensive book of its type.

The proper's liturgical function provides the reader with information regarding the specific feast day (or days) for which particular texts were used. This is useful not only as basic background information but also as a valuable aid to assist in the artistic interpretation of the musical setting of a text. A listing of the feast days of the liturgical year is helpful to church musicians who wish to select music with Latin texts for use in worship services or as an aid for conductors as they program Latin sacred music in concert settings.