There are no established rules or standards by which music is composed. What makes a thing objective is that by its very nature, it must adhere to certain standards or certain logic in order for that thing to be considered what it is. A triangle must, by its very definition, be a polygon with three connected sides whose internal angles add up to 180 degrees. Anything else, and the object would no longer be a triangle, by its very definition. Music, on the other hand, has no such logic or standards. There is no logical definition of music, such that a breach of that logic renders the output something other than music. Therefore, no objective standard exists for the composition or development of music.
Just as music has no logical definition to adhere to, neither can value judgments of music be objectified. There is no standard on which musical value is based. The value of music arises from a completely subjective and internal system -- the inspiration gained from a particular piece of music. Inspiration, by definition, is a subjective element of appreciation. If the subjective is the criteria for valuing music, then no objective value judgments could ever be made.
From these points we clearly see that the creation and appreciation of music is subjective in nature. The individual person makes, consciously or subconsciously, a set of fluctuating criteria by which they internally judge the worth of a selection of music. Some people like Mozart, others don't. Some like Boulez, others don't. This is not a contradiction; it is the recognition that both people are justified in their liking. One has no justification dictating to another what music she should appreciate or find inspiring.
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