Keyboard concertos by Johann Sebastian Bach 1059) which adds an oboe to the strings and continuo. Most of Bach's harpsichord concertos (with the exception of the 5th "Brandenburg Concerto") are thought to be arrangements made from earlier concertos for melodic instruments probably written in Köthen. In many cases, only the harpsichord version has survived. They are among the first concertos for keyboard instrument ever written. The earliest extant sources regarding Bach's involvement with the keyboard concerto genre are his Weimar concerto transcriptions, BWV 592–596 and 972–987 (), and his fifth "Brandenburg Concerto", BWV 1050, the early version of which, BWV 1050a, may have originated before Bach
Horn Concertos (Mozart) Horn Concertos (Mozart) The Horn Concertos by Wolfgang Amadeus Mozart were written for his friend Joseph Leutgeb whom he had known since childhood. Leutgeb was a skilled player, as the works are very difficult to perform on the natural horn of the period, requiring lip trills, much hand-stopping, and rapid tonguing. In addition to the four works listed above, there are two incomplete concerto movements, K. 370b and the Concert Rondo, K. 371, both from 1781 and both in E-flat major, and a 91-bar fragment of the first movement for a concerto in E major (K. 494a), written in 1785