In the 18th century, the term "clavier" was used to refer to almost all keyboard instruments. For this Bach recital, the Austrian harpsichordist Johannes Maria Bogner has taken precisely this into account and uses the harpsichord and the clavichord for his interpretations, whereby he performs the Chromatic Fantasy and Fugue BWV 903 here on both the harpsichord and the clavichord for direct comparison.