The author reflects on Gregorian chants and other sacred music pieces used in Latin Church liturgical celebrations. He discusses motets as music pieces based on an added text or on favorite prayer texts as "Ave Maria." He says that Gregorian chant is the fundamental music of the Roman Rite, that a sung Mass is complete when sung only in chants, and that chants differ as their functions differ, citing as example meditation chants that accompany the lessons, which are elaborate settings of their texts in a style conducive to meditation.