In the depths of winter in 1705 the young Johann Sebastian Bach, then unknown as a composer and earning a modest living as a teacher and organist, set off on a long journey by foot to Lübeck to visit the composer Dieterich Buxterhude, a distance of more than 250 miles. This journey and its destination were a pivotal point in the life of arguably the greatest composer the world has yet seen. Lübeck was Bach's moment, when a young teacher with a reputation for intolerance of his pupils' failings began his journey to become the master of the Baroque.