Piano concertos by Wolfgang Amadeus Mozart it was probably J.C. Bach, whom Mozart admired, who introduced the structural innovation of allowing the keyboard to introduce new thematic material in its first entry. Concertos Nos 1–4 (K. 37, 39, 40 and 41) are orchestral and keyboard arrangements of sonata movements by other composers. The next three concertos (K. 107/1, 2 and 3), which are not numbered, are arrangements of piano sonatas by J.C. Bach (Op 5. Nos. 2, 3, and 4, all composed by 1766). Based on handwriting analysis of the autographs they are believed to date from 1771–72. Concerto No. 5, K. 175 from 1773 was
Brandenburg end, and from 1323 up until 1415 Brandenburg was under the control of the Wittelsbachs of Bavaria, followed by the Luxembourg Dynasties. Under the Luxembourgs, the Margrave of Brandenburg gained the status of a prince-elector of the Holy Roman Empire. In the period 1373-1415, Brandenburg was a part of the Lands of the Bohemian Crown. In 1415, the Electorate of Brandenburg was granted by Emperor Sigismund to the House of Hohenzollern, which would rule until the end of World War I. The Hohenzollerns established their capital in Berlin, by then the economic center of Brandenburg. Brandenburg converted to Protestantism in