 The music generally used in the restored Gallican rite Mass and other services is largely the composition of Maxim Kovalevsky (1903-1988), a deacon in the Russian Orthodox Church and the brother of St John of Saint-Denis.Much of his music for the propers and ordinary of the mass and divine office is an adaptation of classical western plainsong melodies, often harmonised, with some of the ordinary being variants on traditional Russian and Greek chants, adapted according to Kovalevsky's trademark style.Other pieces are entirely his own composition, including such examples as the ancient hymns, "Gloria in Excelsis Deo" and "Let All Mortal Flesh Keep Silence", as well as an a cappella arrangement of the popular Christmas carol, "Il Est Né, le Divin Enfant".