Requiem (from lat. requies "peace", "rest"[1]) is a funeral mass (lat. Missa pro defunctis) in the Catholic Church of the Latin rite. Since the Baroque era, the composer's requiem has been a high genre of sacred concert music, a kind of mourning oratorio. It is called by the initial words of the introite "Requiem aeternam dona eis, Domine" ("Grant them eternal rest, Lord"), which opens the traditional (Gregorian monodic) funeral mass.