Johann Sebastian Bach may have been the first to write harpsichord concertos, and even those concertos are more rewritten than written. With only two likely exceptions (including the Fifth Brandenburg), his 15 concertos for harpsichord are likely reworkings of compositions for other instruments.
We don’t know why he made these arrangements, but they could have been training pieces for his own sons.
The D-minor Harpsichord Concerto shows how diligently Bach studied Vivaldi: the statements of the theme in unharmonized octaves that begin the first two movements and the aggressive cast of the themes in the outer movements are typical Vivaldi touches.
Just listen to the amazing music:
