Brandenburg Concertos his scoring the concertos for "several instruments" ("Concerts avec plusieurs instruments") is an understatement. Bach used the "widest spectrum of orchestral instruments … in daring combinations," as Christoph Wolff has commented. "Every one of the six concertos set a precedent in scoring, and every one was to remain without parallel." Heinrich Besseler has noted that the overall forces required (leaving aside the first concerto, which was rewritten for a special occasion) tallies exactly with the 17 players Bach had at his disposal in Köthen. Title on autograph score: Concerto 1 à 2 Corni di Caccia, 3 Hautb: è Bassono, Violino
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