Stephanie Hughes presents tonight's Bach Prom live from London's Royal Albert Hall on the 250th anniversary of the composer's death. Roger Norrington conducts the Choir of the Enlightenment and the Orchestra of the Age of Enlightenment in a performance of J.S. Bach's Mass in B minor, preceded by the motet Lieber Herr Gott, composed by his son Johann Christoph Bach, which may have been performed at Bach's funeral.