In 1994, an album of chants recorded in the 1970s by Spanish Benedictine Monks was a surprise bestseller. The album reached #3 on the Billboard 200 chart, and was certified double-platinum.
Chant also figures in the soundtrack of the anime Vision of Escaflowne:
And in the theme music of the Xbox game Halo: Combat Evolved:
And in “Sadeness Part I” by the musical project Enigma:
And in Monty Python and the Holy Grail: