One of the loveliest pieces of sacred music that I know is Andrew Lloyd Webber’s rendition of “Pie Jesu.” “Pie Jesu” means “Kind Jesus,” and the Latin text calls on “the Lamb of God” to show mercy to his people. It’s here because mercy is at the heart of Ignatian spirituality.
The text has an interesting history. The “Pie Jesu” is an ancient motet based on the the last couplet of the “Dies Irae,” the hymn of the “Day of Wrath” that was part of the old Latin Requiem Mass. The Vatican II liturgical reforms removed the Dies Irae from the Mass in order to emphasize Christian hope. Many composers set the Pie Jesu to music in Requiems, most notably Gabriel Faure, whose setting evidently influenced Lloyd Webber.
Here is a performance by the single-named Norwegian soprano Sissel.