Keyboard concertos by Johann Sebastian Bach left Weimar in 1717. Many of Bach's orchestral harpsichord concertos are adapted from a model with one or more violin solo parts. Several of these earlier models are extant. The oldest of these is Vivaldi's concerto for four violins, RV 580, published in 1711, model for Bach's concerto for four harpsichords, BWV 1065. Bach replaced the part of his fourth "Brandenburg Concerto", BWV 1049, composed in 1721 or earlier, by a harpsichord part when he reworked it to the harpsichord concerto BWV 1057. Bach's extant violin concertos BWV 1041–1043, two for a single violin soloist and one for two violin
Brandenburg with Poland. Brandenburg originated in the Northern March in the 900s AD from areas conquered from the Wends, and later became the Margraviate of Brandenburg, a major principality of the Holy Roman Empire, with Albert the Bear as prince-elector. In the 17th century Brandenburg came under the rule of the House of Hohenzollern, the rulers of Prussia, who established Brandenburg-Prussia to become the core of the Kingdom of Prussia. Brandenburg became the Province of Brandenburg in 1815, a province within the kingdom and later within the Free State of Prussia. Brandenburg was established as a state in 1945 after World