(A mighty fortress is our God) for soprano, alto, tenor and bass, vocal ensemble, oboe I–III, oboe d’amore I–II, oboe da caccia, taille, trumpet, timpani, organ, strings and basso continuo

Bach’s cantata BWV 80, “A mighty fortress is our God”, is set to Luther’s spirited hymn from 1529 that first entered the Protestant canon after the reformer’s death. The cantata is based on a Weimar composition written in 1715 for Oculi (the Third Sunday in Lent), whose opening bass solo “All that which of God is fathered” quotes the chorale melody “A mighty fortress” as an additional commentary layer. It was perhaps this loose relationship to the chorale that led Bach to reuse the Weimar composition in Leipzig for Reformation Sunday; initially, he added a distinguished chorale setting at the beginning of the work, which he replaced in the 1730s with an extended chorale motet. Bach’s son, Wilhelm Friedemann, later borrowed the first and fifth tutti movements for his own church music in Halle, adding Latin libretti and a choir of trumpets and timpani – instruments that are occasionally used in his father’s version to this day. Despite the compositional mastery of the cantata, a distinct tension is evident between the compositional layers of the Reformation and Oculi settings. While the heroised image of Bach in the 19th century led to performances emphasising the large choral movements, today the intimate nature of the solo Weimar movements does not go unappreciated.