Little is known about these concertos. It is supposed that the seven were formed by putting together various separate movements, or were arrangements or transcriptions for the clavier. “In all the concertos for clavier, whether for one instrument or many, there are passages for the solo instrument unaccompanied which anticipate the procedure of modern concertos, with considerable use of arpeggios, and even occasional cadenza passages. Bach follows the Italian types in the general scheme and easy style of the quick movements, and they are rather homophonic in feeling, with the exception of the last movement of the double concerto in C major, which is a fugue of the most vivacious description.... Bach clearly enjoyed writing in the concerto form and found it congenial. It would be even natural to infer that he found opportunities for performing the works, as in many cases the same concertos appear in versions both for violin and clavier.”[2]

Parry also says: “When Bach writes slow movements for the clavier, he makes them serve as phases of contrast to the quick movements, in which some rather abstract melody is discussed with a certain aloofness of manner, or treated with elaborate ornamentation, such as was more suited to the instrument than passages of sustained melody pure and simple. The alternative presented in the admirable concerto for the clavier in D minor is to give a Siciliano in place of the central slow movement, a course which provides a type of melody well adapted to the limited sustaining power of the harpsichord.... The finest of them [the concertos] is that in D minor, above mentioned, which from its style would appear to have been written at CÖthen.”

It is supposed that there was use of the general bass in these concertos. A second clavier was usually employed; but there is reason to believe that a portable organ, or lutes, theorbos, and the like were also used in accompaniment. Dr. Albert Schweitzer wrote in his J. S. Bach (Leipsic, 1905): “The seven concertos for clavier are in effect, and with one exception only, transcriptions made at Leipsic after 1730 at a time when Bach saw himself obliged to write concertos for the performances of the Telemann Society, which he began to conduct in 1729, and for the little family concerts at his own home. These transcriptions are of unequal worth. Some were made carefully and with art, while others betray impatience in the accomplishment of an uninteresting task. Only one of the pianoforte concertos is not derived from a violin concerto.”