I'm going to start by defining some terms. We may as well start with objective, shall we? When someone makes an objective statement, they are making a statement which is true independent of the observer. With a subjective statement, that statement is only true regarding the observer. An objective statement describes the object; a subjective statement refers to the subject. An objective statement is not an indelible law of the universe, and no one is claiming it is. If you think that everything which is not stamped on the very foundations of the universe is subjective, you should die.
This does get sticky when describing art, because many sentences are both subjective and objective; that is, they make an observation about the object while simultaneously describing how that observation affected the observer. This is called criticism.
Objectivity Objectively Exists, You Fucking Moron
With the terms out of the way, let's begin properly. This first section is just establishing the fact that objectivity objectively exists in art. Let's begin, shall we?
Anyone who argues that there is no such thing as objectivity in art is demonstrably wrong. I'm a writer, so I'm only going to deal with writing, here. If any visual artists or musicians out there would like to provide examples from their own fields, that would be excellent--I know that there's a lot to both of them and I wish I were versed enough to provide examples.
We'll start with the basics. These are on the level of "so basic people probably forget about them." Every story has a word count which describes how long it is. Most novels can be described based on how many chapters there are, and what the plot of the story is, and who the characters are. You can...