Keyboard concertos by Johann Sebastian Bach soloists, were all adapted into harpsichord concertos by the composer, BWV 1058, 1054 and 1062 respectively. It is often assumed that Bach's extant violin concertos were written in his Köthen period (1717–1723): it can however not be proven from documentary evidence that any of them existed prior to around 1730. In September 1725 Bach performed organ music, accompanied by other instruments, in Dresden. The works he performed there have not been identified. More than a year later he composed several cantatas with an organ obligato part. Several movements of such cantatas were derived from earlier lost concertos, and resurfaced in
Organ concertos, Op. 7 (Handel) Organ concertos, Op. 7 (Handel) The Handel organ concertos Op 7, HWV 306–311, refer to the six organ concertos for organ and orchestra composed by George Frideric Handel in London between 1740 and 1751, published posthumously in 1761 by the printing company of John Walsh. They were written for performance during Handel's oratorios, contain almost entirely original material, including some of his most popular and inspired movements. Although a complete version of the first set of organ concertos Op.4 appeared in Handel's lifetime in 1738, many of the concertos of the posthumous Op.7 set have missing movements and sections, where