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
Organ concertos, Op. 4 (Handel) In November and December 1734, Handel presented various opera revivals and a newly composed opera-ballet "Terpsichore". However the combination of dance and opera seria was not sufficient to attract the opera going public. In January 1735 Ariodante opened, but, despite the quality of the music and a visible royal presence, was no more successful. It was in March that Handel started his first oratorio season, featuring the organ concertos HWV 290-293. The timing of the performances avoided conflicts with events in other London theatres and the local papers advertised the "new Concertos on the Organ." In spite of this his