The Theresienmesse, Hob. XXII:12 is a mass in B flat major written by Haydn and nicknamed after Maria Theresa of the Two Sicilies, empress consort of Francis II. The empress herself was the soprano soloist at private performances of both The Creation and The Seasons in 1801 at the Viennese Court. The title does not appear on the autograph score. The Mass is scored for solo quartet, chorus, strings, two clarinets, two trumpets, timpani and organ continuo. While probably not as frequently performed as its companions the Nelson mass or the Missa in tempore belli, the Theresienmesse has attracted critical admiration.
