ABSTRACT
The opportunities for contrast that were implicit in the concerto's middle movement was something of which most composers of our period were only too happy to take advantage, and key- and/or mode-changes for this movement are practically universal. Among the extremely rare exceptions are Paisiello's Concerto no. 3 in A major and Cogan's Op. 5 in C major, both of whose middle movements are in the same key as their first. Generally speaking, in the case of major-key concertos the predilection for middle movements in the dominant or subdominant before 1760 was intensified in the following fifty years, with a preference for the latter. This weighting may have been due to Mozart's usage in the majority of his piano concertos, but it changed dramatically during the years from 1810 to 1850, when keys removed by a third – a rarity before 1770 – became a regular feature. Some of these involve modal change, which had always been an option, of course, and that minority of eighteenth-century works of any genre in minor keys almost always featured an escape to the (relative) major in middle movements, and very often the parallel major in finales as well. Exceptions include J.C. Bach's early set of six concertos, the third of which, in D minor, has a middle movement in B flat major (headed Adagio affettuoso con sordini), and whose sixth, in F minor, has one in C minor (Andante), and Paisiello's Stürmund-Drang-influenced G minor Concerto, whose slow movement (Largo) is in C minor with a central section in E flat major. 1
