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
Margraviate of Brandenburg throne, as they already held the vote of Bohemia. Charles succeeded in purchasing Brandenburg from Margrave Otto for 500,000 guilders in 1373 and, at a in Guben, he attached (but not incorporated) Brandenburg to the Crown of Bohemia. The "Landbuch" ("land book", i.e. estate register) of Charles IV, a source for the history of medieval settlement in Brandenburg, originated during this time. Charles chose the castle of to be the electoral residence. The power of the Luxembourgs in Brandenburg declined during the reign of Charles's nephew Jobst of Moravia. The was pawned to the Teutonic Knights, who neglected the border