The original rhythms of EIN FESTE BURG (see 469) had already reached their familiar isorhythmic (all equal rhythms) shape by the time of Johann S. Bach (PHH 7) in the eighteenth century. The harmonization is taken from his Cantata 80. Many organ and choral works are based on this chorale, including Felix Mendelssohn (PHH 279) in his Symphony and Giacomo Meyerbeer in his opera Les Huguenots.
This rhythmic setting needs a more majestic approach than the one found at 468.
Sing in harmony on stanzas 2 and 3 and in unison on stanzas 1 and 4. Support the singing with strong accompaniment on the organ and/or with use of a brass ensemble.

--Psalter Hymnal Handbook