Organ concertos, Op. 4 (Handel) had already been established during his one-year position as cathedral organist in Halle in 1702. Handel's organ concertos thus have a special place in his oeuvre. They paved the way for Mozart and Beethoven, who like Handel achieved fame in their lifetimes as composers and performers of their own concertos. In the sinfonias of some of his cantatas, Johann Sebastian Bach had already introduced concerto movements for organ and orchestra. However, Bach's organs in both Weimar and Leipzig were large organs with double keyboards and pedals, powerful instruments that could only dominate a baroque orchestra. Bach's organ writing in the
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