The Bach family already counted several composers when Johann Sebastian was born as the last child of a city musician in Eisenach. After being orphaned at the age of 10, he lived for five years with his eldest brother Johann Christoph, after which he continued his musical education in Lüneburg. From 1703 he was back in Thuringia, working as a musician for Protestant churches in Arnstadt and Mühlhausen and, for longer stretches of time, at courts in Weimar, where he expanded his organ repertory, and Köthen, where he was mostly engaged with chamber music. From 1723 he was employed as Thomaskantor (cantor at St Thomas’s) in Leipzig. There he composed music for the principal Lutheran churches of the city, and for its university’s student ensemble Collegium Musicum. From 1726 he published some of his keyboard and organ music. In Leipzig, as had happened during some of his earlier positions, he had difficult relations with his employer, a situation that was little remedied when he was granted the title of court composer by his sovereign, Augustus III of Poland, in 1736. In the last decades of his life he reworked and extended many of his earlier compositions. He died of complications after eye surgery in 1750 at the age of 65.