ABSTRACT
In performing Carl Philipp Emanuel Bach's keyboard concertos, people encounter a lack of information on two extremely important points. These are: for what kind of solo instrument(s) the works were composed; or on what kind of instrument they were performed in the 18th century. In all probability Bach knew and used many different keyboard instruments. He was always very open towards new ideas in instrument building and greeted them enthusiastically – he even admired a curious invention called the 'Bogenclavier'. The Epoch of Bach and 'Empfindsamkeit' was not a period of dogmatism in music and performance. True enough, the known fortepianos by Silbermann have an action based on that of Christofori's fortepianos, but it is adapted to a very heavy case, resembling that of the German harpsichords. This ambivalence towards the choice of instruments may have been a constant factor during the whole of Bach's Hamburg period.
