Keyboard concertos by Johann Sebastian Bach the harpsichord concertos BWV 1052, 1053 and 1059. Based on harpsichord concertos and earlier cantata movements orchestral organ concertos were reconstructed and/or transcribed and arranged. The parts from the Concerto for four harpsichords BWV 1065 (Bach's arrangement of the Concerto for Four Violins, RV 580, by Antonio Vivaldi), have been dated to around 1730. Whereas the concertos with a single harpsichord soloist were composed partly to showcase Bach's own prowess at the keyboard, the others were written for different purposes, one of them being as —music for domestic performance within the Bach household at the Thomaschule in Leipzig. Johann Nikolaus
Piano concertos by Wolfgang Amadeus Mozart elevated to the most prominent position among the instruments. These works, with their alternation of orchestral "tuttis" and passages for solo display, in turn owe their structure to the tradition of Baroque operatic arias, from which the first movements of Mozart's piano concertos inherited their basic ritornello form. A similar structure can also be seen in the violin concerti of, for example, Vivaldi, who established the form, along with the three-movement concerto structure, and Viotti, wherein the concerto is divided into six sections. The keyboard parts of the concertos were almost invariably based on material presented in the ritornelli, and