Gouin has set familiar Gregorian chant Ordinary parts—Kyrie XVI in Greek, Gloria VIII in Latin, Mode VI Alleluia, Sanctus XVIII in Latin, ICEL memorial acclamations in English, ICEL Amen (expanded), and Agnus Dei XVIII in Latin—for Assembly, SATB choir, and organ, with optional Flute, Brass Quintet, Percussion, and Strings. The choral parts sometimes support the assembly chant, and sometimes embellish it. The score is in modern notation, and has been treated with great care to preserve the natural flow of chant. A highlight is the Gloria (Missa de Angelis), which alternates assembly chant with original, metered music for the choir based on the chant.