Richard Maunder and Robert Levin have theorized that this piece intended to include an "Amen fugue."
A movement of this piece ends by reprising the previous movement's closing G minor four-voice fugue at the point marked "Quam olim da capo." This piece's second movement borrows from George Frideric Handel's Dettingen Anthem. Its Lux aeterna ("lucks" AY-turn-uh) movement begins by playing the first two sections of its first movement in reverse order, and ends with the same double fugue as the one in this piece's second movement (*) Kyrie (KEE-ree-ay). Richard Maunder and Robert Levin have theorized that this piece intended to include an "Amen fugue." An Offertorium and a Sanctus are the fourth and fifth of this piece's eight main sections. Its Confutatis (cohn-foo-TAH-tiss) movement is followed by eight bars of the Lacrimosa, at which point this piece originally broke off before being completed by Franz Süssmayr. For 10 points, name this mass for the dead by an Austrian child prodigy.
A movement of this piece ends by reprising the previous movement's closing G minor four-voice fugue at the point marked "Quam olim da capo.
Mozart's requiem [or Wolfgang Amadeus Mozart's Requiem Mass in D minor; prompt on partial answer]