Johann Sebastian Bach - Concertos

Bach’s concertos for keyboard instruments are among the first such works ever written. From 1729 to 1741 the composer was director of the Collegium musicum in Leipzig, a musical society founded by Telemann, often giving concerts at Zimmermann´s coffee-house.
It was for occasions such as these that Bach produced his harpsichord concertos.
There are concertos for one, two, three or four harpsichords; many of them are thought to be arrangements of earlier concertos for other instruments.