Keyboard concertos by Johann Sebastian Bach the harpsichord concertos BWV 1052, 1053 and 1059. Based on harpsichord concertos and earlier cantata movements orchestral organ concertos were reconstructed and/or transcribed and arranged. The parts from the Concerto for four harpsichords BWV 1065 (Bach's arrangement of the Concerto for Four Violins, RV 580, by Antonio Vivaldi), have been dated to around 1730. Whereas the concertos with a single harpsichord soloist were composed partly to showcase Bach's own prowess at the keyboard, the others were written for different purposes, one of them being as —music for domestic performance within the Bach household at the Thomaschule in Leipzig. Johann Nikolaus
Brandenburg Navy Brandenburg Navy had almost thirty active warships. These ships were used primarily to secure control over hostile trade routes and maritime trading, as blockades and to provide naval defence, and to also provide reinforcement on various military operations, which would frequently involve engagements with unfriendly warships. In 1682, Frederick William, the prince-elector of Brandenburg, who was intensely involved in the navy's affairs, secured the navy a base at Greetsiel, but they shifted to Emden a year later. Frederick William died in 1688, and his descendants took no interest in the Brandenburg Navy. Frederick III and his grandson Frederick the Great