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
Oberliga Berlin-Brandenburg each who would determine their champions in a home-and-away format. The two divisional champions would then play for the Brandenburg championship in a two-game series. Should each team win one game, a third game was held as a decider. The Brandenburg champion would then continue on to play in the German football championship. From 1925 onwards, the runners-up of Brandenburg was also qualified for an enlarged national championship. Below the league, as the second division in Brandenburg, four "Kreisligas" were set, those being: From 1925 onwards, until 1931, the league was dominated by Hertha BSC Berlin, who won it every