accompaniment. Bach gave one of the two upper voices to the harpsichord (right hand), thus giving a concertato role to the instrument. He goes further than the traditional format in giving more than one upper voice to the harpsichordist’s right hand in some instances, and other variant formats.
For the first five sonatas the succession of movements follows the sonata da chiesa four-movement model, that is starting with a slow movement, followed by a fast movement, and again a slow and a fast movement. The last sonata starts with an Allegro. After a few slow and fast movements, the sonata ends with an Allegro. BWV 1014 is considered history’s very first modern duo sonata.Within the framework of the sonata da chiesa, Bach explores diverse forms such as those of the aria and the concerto.