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
Province of Brandenburg the Bear, another Saxon count from the noble House of Ascania, who established the Margraviate of Brandenburg in 1157. His son Margrave Otto I already achieved the dignity of an Arch-Chamberlain of the Holy Roman Empire in 1177. Emperor Charles IV by the Golden Bull of 1356 confirmed the electoral dignity of the Brandenburg margraves and in 1373 assigned the electorate to his son Wenceslaus in 1373. The Elector of Brandenburg held the seventh rank among the electors of the Empire and had five votes in the Council of Princes. In 1415 Brandenburg was acquired by Burgrave Frederick of Nuremberg,