Prelude: Fugue in d minor (the fiddle). Bach transcribed this fugue for organ from the original fugue found in the Sonata for Solo Violin No.1 in G minor BWV 1001. Here is the link to the original: The organ version has a different BWV number BWV 539 and a different key of d minor. Here is a link to the organ transcription: [I won’t be using the tremulant]. Bach and indeed many Baroque composers, especially George Fredrick Handel, made a number of transcriptions from one musical medium to another and moreover “copied” and rewrote complete pieces when they needed to write “new music” and were running out of time.