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
Organ concertos, Op. 4 (Handel) In November and December 1734, Handel presented various opera revivals and a newly composed opera-ballet "Terpsichore". However the combination of dance and opera seria was not sufficient to attract the opera going public. In January 1735 Ariodante opened, but, despite the quality of the music and a visible royal presence, was no more successful. It was in March that Handel started his first oratorio season, featuring the organ concertos HWV 290-293. The timing of the performances avoided conflicts with events in other London theatres and the local papers advertised the "new Concertos on the Organ." In spite of this his