image:Heilige mis voetgebeden.jpg The Requiem (from Latin requiem, accusative case of requies, rest) or Requiem Mass (informally, a funeral Mass), also known formally (in Latin) as the Missa pro defunctis or Missa defunctorum ("mass for the departed" or "mass of the departed," respectively), is a liturgical service of the Roman Catholic Church, Anglo-Catholic Anglicans, as well as certain Lutheran Churches in the United States. There is also a requiem, with a wholly different ritual form and texts, that is observed in the Eastern Orthodox and Eastern Catholic Churches. The common theme of requiems is prayer for the salvation of the soul(s) of the departed, and it is used both at services immediately preceding a burial, and on occasions of more general remembrance.

"Requiem" is also the title of various musical compositions used in such liturgical services or as concert pieces as settings of the portions of that Mass which have been traditionally sung in the Roman Catholic liturgy.

While prayers in the regular Mass, such as the Introit and Gradual change according to the Calendar of Saints, the text for the requiem Mass is particularly fixed. Originally such funeral musical compositions were meant to be performed in liturgical service, with monophonic chant. Eventually the dramatic character began to appeal to composers to an extent that they made the requiem a genre of its own.

The Roman Rite liturgy

This use of the word requiem comes from the opening words of the Introit: Requiem æternam dona eis, Domine, et lux perpetua luceat eis. (Eternal rest grant unto them, O Lord, and let light perpetual shine upon them.) The requiem form of the Tridentine Mass differs from the ordinary Mass in omitting certain joyful passages, such as the Alleluia, in never having the Gloria or the Credo, in adding the sequence Dies Iræ, in altering the Agnus Dei, in replacing Ite missa est with Requiescant in pace, and in omitting the final blessing. These distinctions have not been kept in the Roman Rite as revised after the Second Vatican Council.

The regular texts of the musical portions to be found in the Roman Catholic liturgy are the following:

• Introit:

''Requiem æternam dona eis, Domine,

''et lux perpetua luceat eis.

''Te decet hymnus Deus, in Sion,

''et tibi reddetur votum in Ierusalem.

''Exaudi orationem meam;

''ad te omnis caro veniet.

''Requiem æternam dona eis, Domine,

et lux perpetua luceat eis.

Eternal rest grant unto them, O Lord,

and let perpetual light shine upon them.