Piano Concertos K. 107 (Mozart) that publication). Therefore, when these works are enumerated with the rest, it can be seen that Mozart composed 30 keyboard concerti. These three works, however, and the concerti numbered as Piano Concertos 1 through 4 are actually not original compositions, but arrangements of works by other composers. 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
Twelve Concertos, Op. 7 (Vivaldi) Twelve Concertos, Op. 7 (Vivaldi) A set of twelve concertos was published by Estienne Roger in 1716-1717 under Antonio Vivaldi's name, as his Opus 7. They were in two volumes, each containing concertos numbered 1-6. Of the set, ten were for violin solo; the other two were for oboe solo. The authenticity of some of the works included has long been doubted by scholars. Three are now considered spurious (i.e. not in fact by Vivaldi) for stylistic reasons. They are: No. 1 in B-flat major for oboe, RV Anh. 143 (formerly RV 465); No. 7 in B-flat major for oboe,