J.S. Bach’s cantatas for every Sunday and feast day of the church year were closely associated with the texts of the readings at the main morning service, and would provide a commentary and reflection on the scripture in question. To many, music had the potential to inspire a depth of emotional engagement as no other art could. Inspired by Luther’s supreme regard for both music and preaching, the cantata provided a focal point in the service that in turn led directly to the sermon. The six cantatas that make up the cycle that is the Christmas Oratorio are no exception to this pattern. Each cantata was first performed separately for the six successive celebrations during Christmas of 1734–5. The printed libretto produced so that the Leipzig congregations could read the text in advance shows that the cycle began with the performance of Part 1 in both main churches (the Thomaskirche and the Nikolaikirche) on Christmas Day, with Part 2 performed twice on St Stephen’s day; Part 3 was performed on 27 December (St John’s Day) and Part 4 on 1 January in both churches to celebrate the feast of the Circumcision (coinciding with New Year); Part 5 was heard on the following day (the first Sunday after New Year) and Part 6 on 6 January, in both churches, for the feast of Epiphany.

While much of the Biblical text in ordinary cantatas is presented in short quotations
or paraphrased in modern poetry, the Christmas Oratorio is so called by virtue of its presentation of the Gospel narrative of the Nativity (Luke 2:1–21 and Matthew 2:1–12), something that renders the work analogous to other familiar oratorios based directly on biblical stories. Daniel Melamed’s recent work suggests that Bach found the precedent for a cyclic work performed over several days in recent Passion cycles rather than in any piece designed specifically for Christmas. Although none of the Christmas festivals singly permitted a piece much longer than a standard cantata (and, in Leipzig, Passions could only be performed on Good Friday), the range of possible services at Christmas meant that an oratorio could be constructed as six discrete cantatas that together would cover the entire narrative. It may be then that Bach was largely responsible for adapting the multi-part Passion genre for Christmas, although there are obvious precedents for single-occasion settings of the Christmas narrative, such as those by Heinrich Schütz and the former Leipzig cantor Thomas Schelle.