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) ornamentation supplied by Smith and have been recorded by Erato. Two modern performing editions of the concertos by the organists and musicologists Peter Williams and Ton Koopman provide missing movements and give suggestions for the ad libitum passages, possibly too earthbound according to some commentators. The recordings of the organists George Malcolm (1976) and Richard Egarr (2009) give further possibilities, which have so far not appeared in printed editions. 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