Gott der Herr ist Sonn und Schild, BWV 79

Gott der Herr ist Sonn und Schild
BWV 79
Church cantata by J. S. Bach
Luther's Ninety-five Theses, beginning the Reformation
Occasion	Reformation Day
Bible text	Psalms 84:11
Chorale	"Nun danket alle Gott" by Martin Rinckart "Nun laßt uns Gott dem Herren" by Ludwig Helmbold
Performed	31 October 1725 (1725-10-31): Leipzig
Movements	6
Vocal	SATB choir and soloists
Instrumental	2 horns timpani 2 oboes 2 violins viola continuo

Johann Sebastian Bach composed the church cantata Gott der Herr ist Sonn und Schild (God the Lord is sun and shield),^[1] BWV 79, in Leipzig in 1725, his third year as Thomaskantor, for Reformation Day and led the first performance on 31 October 1725.

The text was written by an unknown poet, who did not refer to the prescribed readings for the day. Bach began the libretto for the feast with a quotation from Psalm 84 and included two hymn stanzas, the first from Martin Rinckart's "Nun danket alle Gott", associated with Reformation Day in Leipzig, as the third movement, and as the last movement the final stanza of Ludwig Helmbold's "Nun laßt uns Gott dem Herren". Bach composed a work of "festive magnificence", structured in six movements, with an aria following the opening chorus, a pair of recitative and duet following the first chorale. He scored the work for three vocal soloists, a four-part choir, and a Baroque instrumental ensemble of two horns, timpani, two transverse flutes (added for a later performance), two oboes, strings and continuo. He achieved a unity within the structure by using the horns not only in the opening but also as obbligato instruments in the two chorales, the first time even playing the same motifs.

Bach performed the cantata again, probably in 1730. He later reworked the music of the opening chorus and a duet again in his Missa in G major, BWV 236, and the music of an alto aria in his Missa in A major, BWV 234.