Vesperae solennes de confessore

"Vesperae solennes de confessore (Solemn Vespers for a Confessor)", K. 339, is a sacred choral composition, written by Wolfgang Amadeus Mozart in 1780. It is scored for SATB choir and soloists, violin I, violin II, 2 trumpets, 3 trombones "colla parte", 2 timpani, and basso continuo (violoncello, double bass, and organ, with optional bassoon obbligato).
The setting was composed for liturgical use in the Salzburg Cathedral. The title "de confessore" was not Mozart's own, and was added by a later hand to his manuscript. It suggests that the work was intended for vespers held on a specific day on the liturgical calendar of saints ("confessors"); however, the saint in question has not been conclusively established if there even was one. This was Mozart's final choral work composed for the cathedral.
Structurally, it is very similar to "Vesperae solennes de Dominica" (K. 321), composed in 1779. The setting is divided into 6 movements; as in "Dominica", a setting of the Minor Doxology (Gloria Patri) concludes all movements, each recapitulating the opening themes. The first three psalms are scored in a bold, exuberant manner, contrasting with the strict, "stile antico" counterpoint of the "a cappella" fourth psalm, and the tranquility of the fifth movement. The Magnificat sees a return to the style of the opening settings.