What is special task did Bach perform while learning to compose?

While learning to compose, Johann Sebastian Bach performed a special task for his brother, Johann Christoph Bach, who was the organist at the Michaeliskirche in Ohrdruf. Bach's brother asked him to copy out a collection of organ tablature by the renowned composer Georg Böhm. This task involved meticulously transcribing complex musical scores, which provided Bach with an in-depth understanding of Böhm's compositional techniques and styles. Through this process, Bach absorbed valuable insights and influences that shaped his own compositional development, contributing to his mastery of organ music and keyboard writing.