I differ from you about the analogy between music and her sister sciences, poetry and painting. The mathematical relationship between poetic syllables and musical sounds, has little to do with their congenial powers over the human mind. The real sources of the picturesque, and the stimulative effects of musical sounds, result from the judicious intermixture of discords, hurrying and clashing in descriptive or in animating harshness. The changes into the flat keys express, according to their different combinations, grief, complaint, patience, sullenness, despair; while indignation, terror, or horror are expressed, or excited by what are called the extreme sharps. When the pleasanter keys are resumed, the mind seems relumined; and this is what professors mean when they talk of the light and shade of a concerto or a song. The soft slow tones, avoiding all violent transitions, and sliding into those agreeable changes of key, which naturally present themselves, banish the painful sympathies, and sooth the spirits in people who, from certain corporal organization, have a native sensibility of musical combinations. Without that conformation, which enables them easily to catch and to express melodies, no strength of understanding, no philosophic research, will empower them to become acquainted with the real effects of music upon the passions. Even where this favourable conformation exists, it is yet necessary to acquire some practical knowledge of the science, at least to live in habits of attending to the ideas and feelings excited by the artful mixtures and transitions of harmony, ere we can justly appreciate its powers. 

I may, without presumption, speak upon this subject, who have studied the science of music with some assiduity, nearly twenty years.