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
Hansa-Brandenburg B.I Hansa-Brandenburg B.I The Hansa-Brandenburg B.I was an unarmed military trainer and reconnaissance biplane of World War I, flown by the Austro-Hungarian Air Service. Early models were known internally to the Hansa-Brandenburg firm as the type D, while later models with a more powerful engine were designated FD. This aircraft was one of the earliest designs of Ernst Heinkel, who was working for Hansa-Brandenburg at the time. It was an entirely conventional two-bay biplane with staggered wings of unequal span. The pilot and observer sat in tandem in a long open cockpit. The aircraft was produced under license by Aero, both