in a few exceptional movements the upper keyboard part is directly related to the violin part: in bwv 1015/3, the two upper parts play in strict canon over broken semiquaver chords in the bass; in bwv 1016/3 in trio sonata form, the two upper parts share the same material, with invertible counterpoint and imitation; in bwv 1014/3, the right hand part adds an imitative subordinate voice to the melody line in the violin, often accompanying in thirds. in bwv 1014/1 and bwv 1016/1, there are instances when the violin and upper keyboard respond to each other, with one borrowing the thematic material of the other. in these last two movements the violin and the upper keyboard are equally matched partners.