The Largo from Bach’s Keyboard Concerto in F minor (BWV 1056) has to be one of the most sublime movements ever written. Scholars think that Bach may have adapted it from his Oboe Concerto in F major. The movement is also used as the Sinfonia in his Cantata 156.
Interestingly, this movement closely resembles the opening movement of a flute concerto by Telemann. Although we cannot know definitively, experts feel that Telemann was the originator of this musical material. Bach then adapted it for his own purposes.
Now often referred to as the Bach Arioso, flutists, violinists, cellists, guitarists and other instrumentalists have claimed this work over the years, using it as a standalone piece or as encore material. It is yet another great example of the flexibility and adaptability of Bach and his contemporaries.