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 broke out, with Brandenburg-Prussia involved as an ally of the Dutch Republic. This alliance was based on a treaty of 1669, and resulted in French occupation of Brandenburg-Prussian Cleves. In June 1673, Frederick William abandoned the Dutch alliance and concluded a subsidy treaty with France, who in return withdrew from Cleves. When the Holy Roman Empire declared war on France, a so-called "Reichskrieg", Brandenburg-Prussia again changed sides and joined the imperial forces. France pressured her ally Sweden to relieve her by attacking Brandenburg-Prussia from the north. Charles XI of Sweden, dependent on French subsidies, reluctantly occupied the Brandenburgian Uckermark in