Music is a form of Reason
Disclaimer: I have not received any rigorous training in Arts (except some musical). Read this article as personal rambling instead of professional opinion.
Music is a form of Reason.
From the mathematical subdivision of bars and beats, to the frequency relations between harmonious note combinations, Music is filled with structure and similarity. The word “reason” comes from Latin “ratiō”, a callout and reminder to the olden days, when Pythagoreanists explored music using numbers.
Unlike Painting, which heavily owes its origin and inspiration to imitation of Nature, Music feels more like an abstract human construction. It's true that Music sometimes borrows from Nature (such as instruments mimicking the sound of birds or rivers), but musical beauty usually lies in repetition and coherence, the same reason why meter, rhyme, and alliteration are valued in poetry.
In this spirit, Music resembles Mathematics and Logic, and some Architecture: it is a kind of formalism, a celebration of Pattern itself, a masterpiece of the human mind.
Therefore, I consider Music a form of Reason.