Brandenburg Concertos been debated what instrument Bach had in mind for the "fiauti d'echo" parts. Nowadays these are usually played on alto recorders, although traverse flutes are sometimes used instead: it is also theorized Bach's original intent may have been the flageolet. In some performances, such as those conducted by Nikolaus Harnoncourt, the two recorders are positioned offstage, thus giving an "echo" effect. Bach adapted the 4th Brandenburg concerto as a harpsichord concerto, BWV 1057. Title on autograph score: Concerto 5 à une Traversiere, une Violino principale, une Violino è una Viola in ripieno, Violoncello, Violone è Cembalo concertato. "Concertino": harpsichord, violin,
Brandenburg-Prussia the Catholic-Imperial camp in the Treaty of Königsberg (1627) and accept garrisons. When the Swedish Empire entered the war and advanced into Brandenburg, George William again claimed neutrality, yet Gustavus Adolphus of Sweden compelled George William to join Sweden as an ally by occupying substantial territory in Brandenburg-Prussia and concentrating an army before the town walls of Berlin. George William did not conclude an alliance, but granted Sweden transit rights, two fortresses and subsidies. Consequently, Roman Catholic armies repeatedly ravaged Brandenburg and other Hohenzollern lands. During the Thirty Years' War, George William was succeeded by Frederick William, born 1620, who