John Eliot Gardiner conducts the English Baroque Soloists and the Monteverdi Choir. This performance was filmed at the Palau de la Musica Catalana, Barcelona in Dec. 1991.
A Requiem Mass in the Roman Catholic tradition is a service designed to pray for the souls of the departed. The parts of the liturgy that are meant to be sung are what constitute all Requiem Mass compositions, including Mozart's.
The structure is as follows: 1. Introit 2. Kyrie 3. Sequence: a. Dies irae b. Tuba mirum c. Rex tremendae d. Recordare e. Confutatis f. Lacrimosa 4. Offertory: a. Domine Jesu Christe b. Hostias 5. Sanctus 6. Benedictus 7. Agnus Dei 8. Lux Aeterna
Mozart died before finishing the Requiem Mass, and his wife Constanze gave the task of finishing the work to a pupil of Mozart's named Süssmayr. From the Sanctus onward, the Requiem is the creation of Süssmayr, though he did use portions of the Introit and Kyrie for the Lux Aeterna.
Despite, or maybe partially because of, the controversy surrounding this Requiem Mass, it is widely regarded as Mozart's greatest masterpiece.
Below is the Latin and the English translation for the Rex tremendae.