Bach lived and worked in Leipzig from 1723 until the end of his life. He was Kantor of the Thomaskirche, with responsibility for the music of the five principal city churches. In 1729 he also took on the direction of the university Collegium Musicum. This mixture of responsibilities drove the breadth of his compositions during this period. While his post as Kantor required the regular production and performance of church music, he also provided music for the university Collegium and wrote or re-arranged a number of important works for the keyboard.

Bach's Magnificat was first performed in 1723, shortly after his arrival in Leipzig. While the Thomaskirche used a German version of the Magnificat each week, the work was by tradition performed in Latin during the most important feasts of the church year. Bach's setting, which was initially designed to be performed at Christmas, therefore included interpolated texts appropriate to the season. Several years later, Bach revised the work and removed these sections, so making it suitable for performance throughout the church year. At the same time he re-wrote the work slightly, changing some of the orchestral scoring and transposing the work from E-flat Major to D major.

The text, from Luke's gospel, is Mary's response to the Annunciation - the news that she is to bear a child who will be the son of God. It is a song of praise and reverence, a key element of Catholic and Protestant liturgy. In the Baroque era, composers such as Monteverdi broke the canticle into small sections, thereby using the music to explore the emotional content of individual phrases.

Bach's approach follows this tradition, interspersing vibrant chorus numbers with more reflective solo arias. It is not over-elaborate: there are no recitatives, no da capo arias. Yet the scoring is rich and would have used one of the largest ensembles to be assembled at the Thomaskirche in Bach's time. Bach makes use of several of the musical conventions of his time - a descending melody on deposuit, (he hath put down), the sudden choral entry at omnes generationes, (all generations), a jagged counterpoint on dispersit (he hath scattered) - while interweaving subtleties of musical expression to create a work which is at once intensely personal yet universal.