This collection of keyboard music was compiled as instructional material for Bach's eldest son. Many of the pieces are easy enough to work well on the guitar. This one, however, requires an agile left hand. It is titled 'Prelude' but has the form and texture of a fughetta and, since it is here in the key of A major, makes a suitable companion piece to Prelude 21 from the Well Tempered Clavier, Book 1. [2 pages, 97KB].