section_path: Compositions/Copies, arrangements and uncertain attributions
section_name: Copies, arrangements and uncertain attributions
paragraph_text: Copies, arrangements and uncertain attributions
  
  In his early youth, Bach copied pieces by other composers to learn from them. Later, he copied and arranged music for performance or as study material for his pupils. Some of these pieces, like " Bist du bei mir " (copied not by Bach but by Anna Magdalena), became famous before being dissociated with Bach. Bach copied and arranged Italian masters such as Vivaldi (e.g. BWV 1065), Pergolesi (BWV 1083) and Palestrina (Missa Sine nomine), French masters such as François Couperin (BWV Anh. 183), and, closer to home, various German masters including Telemann (e.g. BWV 824 = TWV 32:14) and Handel (arias from Brockes Passion), and music from members of his own family. He also often copied and arranged his own music (e.g. movements from cantatas for his short masses BWV 233–236), as his music was likewise copied and arranged by others. Some of these arrangements, like the late 19th-century " Air on the G String ", helped to popularise Bach's music.
  
  Sometimes, "who copied whom" is not clear. For instance, Forkel mentions a Mass for double chorus among the works composed by Bach. The work was published and performed in the early 19th century. Although a score partially in Bach's handwriting exists, the work was later considered spurious. In 1950, the design of the Bach-Werke-Verzeichnis was to keep such works out of the main catalogue: if there was a strong association with Bach they could be listed in its appendix (German: Anhang, abbreviated as Anh.). Thus, for instance, the aforementioned Mass for double chorus became BWV Anh. 167. But this was far from the end of the attribution issues. For instance, Schlage doch, gewünschte Stunde, BWV 53, was later attributed to Melchior Hoffmann. For other works, Bach's authorship was put in doubt without a generally accepted answer to the question of whether or not he composed it: the best-known organ composition in the BWV catalogue, the Toccata and Fugue in D minor, BWV 565, was indicated as one of these uncertain works in the late 20th century.