Brandenburg-Schwedt his dominions and furnishing his castle in a Baroque style at great expense. His younger brother Albert Frederick (1672–1731) became a general lieutenant and Grand Master of the Order of Saint John; the third-born, Charles Philip (1673–1695) likewise became an officer and shortly before his death secretly married the Piemontese noblewoman Caterina di Balbiano, who called herself "Madame de Brandebourg" as a widow. The youngest of Dorothea's sons was Margrave Christian Ludwig (1677–1734), officer and administrator of Halberstadt, the honoree of Bach's "Brandenburg Concertos". The brisk building activity was continued by Philipp William's son and successor, Margrave Frederick William (1700-1771).
Keyboard concertos by Johann Sebastian Bach timing matched the publication of the first ever collection of keyboard concertos, the widely acclaimed and well-selling Organ concertos, Op.4 of George Frederic Handel published in London and Paris in 1738. The harpsichord concertos were composed in a manner completely idiomatic to the keyboard (this was equally true for those written for two or more harpsichords). They were almost certainly originally conceived for a small chamber group, with one instrument per desk, even if performed on one of the newly developed fortepianos, which only gradually acquired the potential for producing a louder dynamic. The keyboard writing also conforms to a