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-Schwedt Brandenburg-Schwedt Brandenburg-Schwedt was a secundogeniture of the Hohenzollern margraves of Brandenburg, established by Prince Philip William who took his residence at Schwedt Castle in 1689. By appanage, they administered the manors of Schwedt and Vierraden on the Oder river (Uckermark and Neumark) as well as Wildenbruch in Pomerania (present-day Swobnica, Poland). Though prosperous, the cadet branch never obtained Imperial immediacy. Because of a lack of money in the late days of the disastrous Thirty Years' War (1618–1648), the "Great Elector Frederick William of Brandenburg in about 1640 mortgaged the Schwedt region to the Baltic German noble Gustav Adolf von (Varrensback,