The other hypothesis elaborated by Williams is that BWV 565 may have been a transcription of a lost solo violin piece. Parallel octaves and the preponderance of thirds and sixths may be explained by a transcriber's attempt to fill in harmony which, if preserved as is, would be inadequately thin on a pipe organ. This is corroborated by the fact that the subject of the fugue, and certain passages (such as bars 12–15), are evidently inspired by string music. Bach is known to have transcribed solo violin works for organ at least twice: the first movement of the Partita in E major for solo violin, BWV 1006, was converted by Bach into the solo organ part of the opening movement of the cantata "Wir danken dir, Gott, wir danken dir", BWV 29. Bach also transcribed the Fugue movement of Sonata in G minor for solo violin, BWV 1001, as the second half of Prelude and Fugue in D minor for organ, BWV 539.