The prelude and fugue have the structure of the first and last movements of an Italian concerto grosso, which has led to suggestions that they might be transcriptions of a lost instrumental work. In the concerto BWV 1044, Bach reworked both the prelude and fugue around the harpsichord part by adding ripieno ritornello sections. In the first movement there is an eight bar ritornello that begins with the opening semiquaver motif of the prelude, which is then heard in augmented form before breaking into distinctive triplet figures: