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-Schwedt Brandenburg-Schwedt Brandenburg-Schwedt was a secundogeniture of the Hohenzollern margraves of Brandenburg, established by Prince Philip William who took his residence at Schwedt Castle in 1689. By appanage, they administered the manors of Schwedt and Vierraden on the Oder river (Uckermark and Neumark) as well as Wildenbruch in Pomerania (present-day Swobnica, Poland). Though prosperous, the cadet branch never obtained Imperial immediacy. Because of a lack of money in the late days of the disastrous Thirty Years' War (1618–1648), the "Great Elector Frederick William of Brandenburg in about 1640 mortgaged the Schwedt region to the Baltic German noble Gustav Adolf von (Varrensback,