ABSTRACT
Bach came to Cöthen late in 1717 and remained there until spring 1723. At Cöthen he had no duties as a church musician, and thus it is assumed that he concentrated on the production of secular music for the court, as well as pedagogical works for his pupils, including members of his own growing family. It was during this period that some of his best-known instrumental works, the Brandenburg Concertos and the works unaccompanied violin, were revised and put into defi nitive form, if not actually composed. Cöthen autographs survive not only for those works but also the fi rst part of the Well-Tempered Clavier (WTC1) and the Inventions and Sinfonias. In addition, the Cöthen years saw the commencement of little keyboard books (Clavierbüchlein) for Wilhelm Friedemann and Anna Magdalena Bach.
