Plato, from a footnote in The Colloquy of Monos and Una, Edgar Allen Poe

It will be hard to discover a better [method of education] than that which the experience of so many ages has already discovered, and this may be summed up as consisting in gymnastics for the body, and _music_ for the soul… For this reason is a musical education so essential; since it causes Rhythm and Harmony to penetrate most intimately into the soul, taking the strongest hold upon it, filling it with _beauty_ and making the man _beautiful-minded_.