The renewed interest in early music in the late 19th century left its mark on 20th-century music. Gregorian influences in classical music include the choral setting of four chants in "Quatre motets sur des thèmes Grégoriens" by Maurice Duruflé, the carols of Peter Maxwell Davies, and the choral work of Arvo Pärt. Gregorian chant has been incorporated into other genres, such as London Boys's "Requiem" and some other dance compositions, Enigma's "Sadeness (Part I)", the chant interpretation of pop and rock by the German band Gregorian, the New age project Era, the techno project E Nomine, many of the songs by American Power/Thrash metal band Iced Earth, and the work of black metal band Deathspell Omega. The modal melodies of chant provide unusual sounds to ears attuned to modern scales. It has also been used in The Omen's main theme, Ave Satani.
*''Graduale triplex'' (1979). Tournai: Desclée& Socii. ISBN 2-85274-094-X