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
Hansa-Brandenburg Hansa-Brandenburg Hansa und Brandenburgische Flugzeugwerke (more usually just Hansa-Brandenburg) was a German aircraft manufacturing company that operated during World War I. It was created in May 1914 by the purchase of "Brandenburgische Flugzeugwerke" by Camillo Castiglioni, who relocated the factory from Liebau to Brandenburg an der Havel. Brandenburg's chief designer, Ernst Heinkel was retained by the new enterprise. By Autumn 1915, it had become the largest aircraft manufacturer in Germany, with a capital of 1,500,000 Marks, 1,000 employees, and two more factories - one in Rummelsburg, Berlin, and one in Wandsbek, Hamburg. Although manufacturing was carried out in Germany, Castiglioni