Piano Concertos K. 107 (Mozart) that publication). Therefore, when these works are enumerated with the rest, it can be seen that Mozart composed 30 keyboard concerti. These three works, however, and the concerti numbered as Piano Concertos 1 through 4 are actually not original compositions, but arrangements of works by other composers. Piano Concertos K. 107 (Mozart) The Piano Concertos, K. 107 are three keyboard concertos by Wolfgang Amadeus Mozart, based on sonatas by Johann Christian Bach. These sonatas are from J.C. Bach's Op. 5; Mozart turned Sonata No. 2 in D, Sonata No. 3 in G, and Sonata No. 4 in E from this
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