Heaven's Secret Requiem, Vol. 4 (Original Game Soundtrack)

A requiem is a musical setting of the Roman Catholic Mass for the Dead (Missa pro defunctis). Historically rooted in Latin liturgy, it sets movements such as the Introit, Kyrie, (historically) the Sequence Dies irae, Offertory, Sanctus, Agnus Dei, and Communion, and often includes additional responsories like Libera me and In paradisum. While the earliest requiems were monophonic chants, the genre became a showcase for polyphonic and later symphonic choral writing. Renaissance composers wrote austere, modal settings; Classical and Romantic composers expanded the forces and dramatic scope; and 20th–21st century composers reimagined the form with new languages, from neo-modal and impressionistic harmonies to avant‑garde sonorities. Today, requiems appear both in liturgy and as concert works, symbolizing collective mourning, remembrance, and spiritual reflection.