We know that Mozart held his Vespers in high regard since he once asked his father, in a letter dated 12 March 1783, to send the two works to him in Vienna so that he could show them to Baron Gottfried van Swieten.  The Office hymns designated as Vesperae de Dominica K. 321 and Vesperae solennes de Confessore K. 339 contain settings of Psalms 109 (Dixit), 110 (Confitebor), 111 (Beatus vir), 112 (Laudate pueri), 116 (Laudate Dominum) and of the Magnificat canticle.  Each of the Psalms forms an autonomous unit; the Doxology at the end is derived from the themes of the various Psalms.<br>