“I am not ashamed to confess publicly that next to theology there is no art which is the equal of music, for she alone, after theology, can do what otherwise only theology can accomplish, namely, quiet and cheer up the soul of man, which is clear evidence that the devil, the originator of depressing worries and troubled thoughts, flees from the voice of music just as he flees from the words of theology. For this very reason the prophets cultivated no art so much as music in that they attached their theology not to geometry, nor to arithmetic, nor to astronomy, but to music, speaking the truth through psalms and hymns.”

Martin Luther, in a letter (1530) to Catholic composer, Ludwig Senfl.