The setting was composed for liturgical use in the Salzburg Cathedral.[1] 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.[2] This was Mozart's final choral work composed for the cathedral.[3]
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 anticocounterpoint of the a cappella fourth psalm,[3] and the tranquility of the fifth movement. The Magnificat sees a return to the style of the opening settings.
Mozart departs from the structure of K. 321 in this movement. The earlier setting of Laudate Dominum is a highly melismaticsoprano solo, with no choral interlude. In K. 339, the soprano solo is much simpler; the choir quietly enters at the conclusion of the psalm with the Gloria Patri, and the soloist rejoins them at the Amen.
This movement is well known outside the context of the larger work, and is often performed in isolation.[4]
^In the Roman Rite's General Roman Calendar, most days of the year were and are feasts of saints, extending then even to Sundays but certainly apart from them, with male confessors (women saints, as well as martyrs, have different texts) making up a large part of them. At that time not only the antiphons, but also the psalms of such feasts were identical; the situation is rather different from the one following Pope Pius X.'s reform of the Breviary. Thus, Vespers for a Confessor were pretty much Vespers for everyday use.
