This work is best known for the second movement, Air, which was arranged later into Air on a G-string. However the whole thing is lovely.
Bach (1685-1750) wrote it in around 1730. In the original score, Bach wrote the first violin and continuo parts, his son C P E Bach wrote out the trumpet, oboe, and timpani parts, and J S Bach’s student Johann Ludwig Krebs wrote out the second violin and viola parts. This has led some musicologists to conclude that it was first written as a string piece with the other parts added later. So here are both versions. First the full orchestra (which I prefer):
And the strings-only version: