When Bach arrived in Leipzig in 1723, the city had six main churches: the Neuekirche, St Paul’s; St Peter’s; St John’s; St Nicholas’s (the Nicholaskirche) and St Thomas’s (the Thomaskirche). Today, of these only the last two remain, the others having been reduced to rubble by allied bombing in the early 1940s. Bach’s position as Kantor of St Thomas’s, coupled with the post of Civic Director of Music for the city, was one of the most notable musical positions in Germany. The financial security of a municipal employer, as opposed to a private patron, coupled with access to the city’s sixty or so professional, salaried musicians, and the boys of the Thomasschule (the boarding school adjacent to St Thomas’s) for whose musical education and training Bach was responsible, would have been significant attractions. The pupils of the Thomasschule, to whom Bach gave singing, instrumental and Latin lessons, were aged between 12 and 23. Given that, at this time, boys’ voices were not expected to break until they were 17 or 18, Bach could count on solo trebles and altos with a good amount of maturity and musical experience behind them.  

In the early years he was obliged to produce a significant amount of new music for the church, including one new sacred cantata a week for performance at the Sunday morning service at St Thomas’s. As has been mentioned, the St John Passion was written for Good Friday in 1724, Bach’s first Easter in Leipzig. The Magnificat had already been written for Bach’s first Christmas (1723); the Easter Oratorio followed in 1725, the St Matthew Passion in 1727, the St Mark Passion (which no longer survives) in 1731, the Mass in B Minor in 1733, the Christmas Oratorio in 1734, and the six motets variously between 1723 and 1737. With the growing popularity and strength of the protestant movement there followed a necessity for contemporary composers to provide a whole brand-new repertoire of music using the vernacular.