Piano Concertos K. 107 (Mozart) 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 set into the three concertos of K. 107. These concertos remained unpublished in the Alte Mozart-Ausgabe, the first complete edition of Mozart's works, so they were not given a number by the publishers of that edition, Breitkopf & Härtel (as the other 27 concerti were given in
Brandenburg the Province of Brandenburg, again subdivided into the government regions of Frankfurt and Potsdam. In 1881, the City of Berlin was separated from the Province of Brandenburg. However, industrial towns ringing Berlin lay within Brandenburg, and the growth of the region's industrial economy brought an increase in the population of the province. The Province of Brandenburg had an area of and a population of 2.6 million (1925). After World War II, the Neumark, the part of Brandenburg east of the Oder–Neisse line, was transferred to Poland; and its native German population expelled. The remainder of the province became a state