Reformation day
Friday 31 October 2025

October 31st is Reformation Day, to commemorate that on this day in 1517 Martin Luther allegedly (it is disputed) nailed his 95 theses against indulgences on the church door of the Schlosskirche in Wittenberg, thereby sparking the protestant reformation. It is understandbly a major protestant and calvinist holiday.

Reformation Day was of course celebrated in Leipzig, so Bach created three very fine cantatas for that day. Gott der Herr ist Sonn und Schild, BWV 79, written in 1725, was the first cantata he wrote for this day. Ein feste Burg ist unser Gott, BWV 80, is reworked from a lost Weimar cantata, Alles, was von Gott geboren, BWV 80a.

Gelobet sei der Herr, mein Gott, BWV 129, was originally written for Trinity Sunday (first performed June 8th 1727) but most likely also performed on Reformation Day on a later occasion - the lyrics were considered to be suited for that day too.

Music for today

• Gott der Herr ist Sonn und Schild, BWV 79
  (first performance 31 October 1725, Leipzig period)
• Gelobet sei der Herr, mein Gott, BWV 129
  (first performance 7 June 1727, Leipzig period)
• Ein feste Burg ist unser Gott, BWV 80
  (first performance 31 October 1727, Leipzig period)