It isn’t easy to understand why Bach decided to leave Köthen and to take the post of Kantor in Leipzig. It is clear however that many of the deepest pages of the organist born in Eisenach were written in Leipzig; among them, the least known to the general public—and most special—are maybe the triosonatas for organ, full of spirituality and probably composed for the training of his talented son, Wilhelm Friedemann. Before and after these sonatas we will listen some of the most beautiful chorals by Bach: very well-known—for the German parishioners—melodies embellished by adding voices, where Bach demonstrates a technical virtuosity in the musical writing absolutely out of the reach of any other composer in History.