[Stefano's comment deserved a longer answer, so here is a full post on the topic.]

What is Art? Something difficult to define. Most say art should convey an emotion and I do agree with Stefano on this. There’s no need of understanding for emotional communication is something that usually doesn’t happen at the rational level. Trying to define art is mostly useless. Art just feels.

There are styles and languages with immediate and universal emotional effect. Everybody get the same instant feeling of aesthetic beauty when listening to Bach, even if they don’t understand how fugues work. Beauty is something mostly instinctive and doesn’t even require an artist. You could get the same feeling watching a sunset or a landscape. But then, in order to understand why Bach is beautiful you have to analyze your own emotions, the effect that Bach wanted to evoke, get to the inner logical and symbolical structure, see the fabric. At that point you understand what the artist intentionally tried to do. That’s the magic in art: the ability to intentionally evoke emotions and ideas.

There are styles and languages a little harder to understand. That’s usually not because they want to hide, or select their elite audience. That’s because the “a-ha” effect is a powerful emotion-generating device. When meaning and structure suddenly emerge, after some thinking our brain springs emotions. Take for example Escher paintings, or hermetic poetry. Sometimes even math equations can have an artistic effect, if you get to see the harmonic symmetry behind them. If you believe, you can even think they’re what God intentionally tried to create; his signature.

The greatest artists can combine several layers of meaning and symbolic languages so that, when enjoying their work, you get instant feeling but, if you persist, you can also get to the deeper layers and enjoy even more. I guess it all depends on the way human cognition works.