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 Concertos of silver. The autograph manuscript of the concertos was only rediscovered in the archives of Brandenburg by Siegfried Wilhelm Dehn in 1849; the concertos were first published in the following year. The manuscript was nearly lost in World War II, when being transported for safekeeping to Prussia by train in the care of a librarian. The train came under aerial bombardment, and the librarian escaped the train to the nearby forest, with the scores hidden under his coat. In the modern era these works have been performed by orchestras with the string parts each played by a number of players,