Brandenburg Concerto No. 5 "Brandenburg Concertos" takes a central place. Nonetheless around half a dozen of Bach's extant concertos, including some of the "Brandenburg Concertos" and lost models of his later harpsichord concertos, seem to have had their roots in his Weimar period. Most of what Bach may have left with his employer in Weimar perished in a fire destroying Schloss Weimar in the 1770s. In 1719 a new large two-manual harpsichord arrived in the residence of Bach's then-time employer at Köthen. BWV 1050a, an extant early version of the fifth "Brandenburg Concerto", may have been conceived for this instrument, but that seems unlikely
Piano concertos by Wolfgang Amadeus Mozart of "fiddling" with all the themes, instead is left with the ritornellic impression: Mozart truly uses "art to conceal art". One further point of great importance is the interaction between piano and orchestra. In the earlier concertos, such as the not totally successful No. 13 in C major, and even more so, perforce, in the concertos for two and three pianos, the interaction between the two is limited, but the later concertos develop the subtle relations between them to a high degree; for example, in No. 16, K. 451. His later concertos are truly described as concertos for "piano and