<P> The Brandenburg Concertos by Johann Sebastian Bach (BWV 1046--1051, original title: Six Concerts à plusieurs instruments) are a collection of six instrumental works presented by Bach to Christian Ludwig, Margrave of Brandenburg - Schwedt, in 1721 (though probably composed earlier). They are widely regarded as some of the best orchestral compositions of the Baroque era . </P> <P> Bach wrote out the music himself for presentation to the Margrave rather than leaving it to a copyist . While he took the opportunity to revise the music, most likely, it was not freshly composed . He appears to have selected the six pieces from concertos he had composed over a number of years while Kapellmeister at Köthen, and possibly extending back to his employment at Weimar (1708--17). </P>

Who did bach write the brandenburg concertos for