Roman (Gregorian) chant

Roman, or Gregorian, chant, the liturgical chant of the Roman Catholic church, has been practiced in various forms since approximately the seventh century. As preserved in musical manuscripts beginning in the tenth century, the chant consists of unaccompanied melodies (plainsong) set to the Latin texts of the liturgy, including both the Mass and the Office.

Although the chants are named for Saint Gregory the Great (pope 590-604), Gregory's role in shaping the surviving repertory is a matter of conjecture. We do know, however, that Gregory was responsible for standardizing the chants by mode and by their role in the liturgical calendar.

It is fitting that the Book of Psalms serves as the principal source for the chant texts; the beauty of the prose complements the magnificent spirituality of the music--music that indeed resonates with the affirmation of Christ's salvation.

Source

The information about the texts originally appeared on The Goodrich Room: Interactive Tour website.