Bach's Missa of 1733
Bach's Missa of 1733, BWV 232 I (early version), is a Kyrie–Gloria Mass in B minor, composed in 1733 by Johann Sebastian Bach. It is an extended missa brevis (German: Kurzmesse, lit. 'short Mass') consisting of a Kyrie in three movements and a Gloria in nine movements. Bach started to compose it, partly based on earlier work, after the death of his sovereign Augustus the Strong (1 February 1733), dedicating it to the latter's son and successor, Frederick August II, in a letter dated 27 July 1733. At the time, Bach was in his tenth year as Lutheran church musician in Leipzig, while the Catholic court of the sovereign Elector of Saxony was located in Dresden. Bach sent performance parts of his Missa to Dresden while he kept the autograph score in Leipzig. Upon arrival in Dresden, the Mass was not added to the repertoire of the Catholic court chapel, but instead the parts, and Bach's dedication letter, were archived in the sovereign's library.
The composition, also known as Bach's Mass for the Dresden court, is an unusually extended work scored for five-part SSATB soloists and choir with an orchestra having a broad winds section. After reusing some of its music in a cantata he composed around 1745 (BWV 191), Bach finally incorporated the 1733 Missa as the first of four parts of his Mass in B minor, composed/assembled in the last years of his life, around 1748–1749. It seems unlikely that the 1733 Kyrie–Gloria Mass, either in its original form or as part of the Mass in B minor, was ever performed during Bach's lifetime.
The Kyrie–Gloria Mass was not assigned a separate number in the BWV catalogue, but in order to distinguish it from the later complete mass (BWV 232), numbers like BWV 232a and BWV 232I are in use. In 2005 Bärenreiter published the Mass in the New Bach Edition series as Missa, BWV 232 I, Fassung von 1733 (i.e. 1733 version of Missa, BWV 232 I), in a volume of early versions of the Mass in B minor. That volume also contained early versions of the Credo (BWV 232 II) and Sanctus (BWV 232 III) of the later Mass. Bach's Mass for the Dresden court is also referred to as Missa 1733 and "The Missa of 1733". The Bach Digital website refers to the work as "BWV 232/I (Frühfassung)", i.e. early version of Part I of BWV 232.