In its intellectual complexity, its formal incomparability and musical variety, Bach’s oeuvre shines out across the centuries. All composers who have come after him must prepared to be measured against him, for he has elevated the language of music to a universal height whose suprapersonal validity is timeless and which remains “comprehensible” in the deepest meaning of the word beyond all further artistic and social developments. Bach’s spiritual works are an exegesis in the best sense of Bibli...