This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Johann Sebastian Bach, born March 31, 1685 in Eisenach and died July 28, 1750 in Leipzig, was a German composer and organist of the late Baroque period. From 1723 until his death he served as Thomaskantor, the director of music for Leipzig's main Lutheran churches and the St Thomas School, a post that required him to compose new music for every Sunday and feast day of the church year, an ongoing institutional demand rather than the occasional commission most composers of the period worked under.
That weekly obligation shaped the scale of what Bach produced over his nearly three decades in the post: a working composer bound to a church calendar rather than to his own creative timetable, writing cantatas, motets and larger liturgical works to a fixed institutional schedule that left comparatively little room for music written purely on his own initiative, though the largest and best known of his works still emerged from within exactly that constrained, calendar bound working life.
Leipzig itself, rather than any single patron, was the employer that shaped Bach's middle and later career this way: a municipal and church post rather than a court appointment, answerable to a city council and a church consistory rather than to one aristocratic taste, which is part of why the surviving Leipzig output reads as liturgical infrastructure built to serve a whole worshipping city year after year rather than music composed to please one employer's personal preference.