Organ concertos, Op. 4 (Handel) had already been established during his one-year position as cathedral organist in Halle in 1702. Handel's organ concertos thus have a special place in his oeuvre. They paved the way for Mozart and Beethoven, who like Handel achieved fame in their lifetimes as composers and performers of their own concertos. In the sinfonias of some of his cantatas, Johann Sebastian Bach had already introduced concerto movements for organ and orchestra. However, Bach's organs in both Weimar and Leipzig were large organs with double keyboards and pedals, powerful instruments that could only dominate a baroque orchestra. Bach's organ writing in the
John Sigismund, Elector of Brandenburg John Sigismund, Elector of Brandenburg John Sigismund (; 8 November 1572 – 23 December 1619) was a Prince-elector of the Margraviate of Brandenburg from the House of Hohenzollern. He became the Duke of Prussia through his marriage to Duchess Anna, the eldest daughter of Duke Albert Frederick of Prussia who died without sons. Their marriage resulted in the creation of Brandenburg-Prussia. John Sigismund was born in Halle an der Saale to Joachim III Frederick, Elector of Brandenburg, and his first wife Catherine of Brandenburg-Küstrin. He succeeded his father as Margrave of Brandenburg in 1608. In 1611, John Sigismund traveled from