At the time of Mozart's death on December 5, 1791, only the first two movements, Requiem aeternam and Kyrie, were completed in all of the orchestral and vocal parts.
The Sequence and Offertorium were completed in skeleton, with the exception of the Lacrymosa, which breaks off after the first eight bars.
The vocal parts and continuo were fully notated.
Occasionally, some of the prominent orchestral parts were briefly indicated, such as the first violin part of the Rex tremendae and Confutatis, the musical bridges in the Recordare, and the trombone solos of the Tuba Mirum.

What remained to be completed for these sections were mostly accompanimental figures, inner harmonies, and orchestral doublings to the vocal parts.
At the time of Mozart's death on December 5, 1791, only the first two movements, Requiem aeternam and Kyrie, were completed in all of the orchestral and vocal parts. The Sequence and Offertorium were completed in skeleton, with the exception of the Lacrymosa, which breaks off after the first eight bars. The vocal parts and continuo were fully notated. Occasionally, some of the prominent orchestral parts were briefly indicated, such as the first violin part of the Rex tremendae and Confutatis, the musical bridges in the Recordare, and the trombone solos of the Tuba Mirum.
What remained to be completed for these sections were mostly accompanimental figures, inner harmonies, and orchestral doublings to the vocal parts.
Requiem (Mozart)