Johann Sebastian Bach is perhaps the best known of our composers on this evening's program, and perhaps the most famous Baroque composer.  His music is beloved around the world, and has influenced hundreds of composers and performers with his compositions, including Mozart. Bach was a prodigious composer and father.  Between his two wives, Barbara and Anna Magdalena, 26 Bach children were born, and 20 survived to adulthood. Five of Bach's six sons went on to be composers themselves: Johann Christian Bach, Wilhelm Friedemann Bach, Carl Phillip Emanuel Bach, for example. Of all our composers tonight, JS Bach was the one who traveled the least.  He basically stayed in his region of Germany. Born in Eisenach, Bach worked in Arnstadt, Leipzig, Weimar, Mühlhausen and Cöthen, but never left Germany the way other composers did during the same time period.  However, Bach did study the works of important composers, and would have been familiar with the music of Corelli, Vivaldi, Buxtehude, Pergolesi and Pachelbel. In 1721, Bach offered to the Margrave of Brandenburg a collection of 6 concertos, which came to be known as the Brandenburg concerti. The Brandenburgs grow out of Bach's long fascination with the latest concertos of Vivaldi and other Italian composers.

The Sixth Brandenburg Concerto has the darkest sound of any of the six concertos, for here Bach completely omits the violins and flutes, and leaves the highest sounds to the middle-range violas.  As we would expect from a concerto, Bach does contrast solo and tutti groups of instruments, but he does so with minimal resources, since this work is really for a chamber ensemble.  The solo trio of two violas and cello is contrasted with the continuo and two violas da gamba filling in the middle voices.  The viola da gamba, already something of an early instrument by Bach's time, lends a transparent sound that is exotic in a concerto ensemble.  The striking orchestration of this work suggests that it may have been written earlier than the other Brandenburgs, since in Weimar, Bach had written other music with similar low orchestrations.  On the other hand, it may date from early in Bach's time at Cöthen (1717); Prince Leopold, his new employer, was an amateur gambist, and the relatively limited gamba parts in this concerto could perhaps have been meant to give Leopold a chance to play with the ensemble.