Some, of course, believe that art is a uniquely personal and emotional experience for the individual, and that what we bring based on past knowledge and taste. Thus, art is an extremely personal experience, one that is unique and emotional. Different art speaks differently to the individual based on their own interpretation or likes/dislikes. For some, art was supposed to tell a story (e.g. The romantics); for others, art told the story, but in a more general, societal manner; and yet still others peel away the emotion of art and say that art is compositional, and it is not about how the art makes one feel, as much as it is as to how art expresses parts of the society in question For this writer, art is experimental; it maybe formal or informal, but it is about the emotional quality of a piece of music, a sculpture, a poem, a novel, or a painting. It has less to do with the deconstruction of the piece (parts explained), and more to do with the synthesis (sum of the parts) and how those parts act in congruence to give one a sense of some emotion. Thus, art is evocative but still individualistic.

As for formal...

Things may not always be noticed by the layperson, and a formal analysis gives one the chance to understand technique, reasons for inclusion of certain brushstrokes or instrumentation, and perhaps even a background of the emotional state that the artist may be been in when composing. We can certainly tell the difference in style between a Rembrandt and a Picasso, yet both are equally viable as art. What separates the two is our own interpretive knowledge of the work, and how understanding it in a formal manner will contribute to our understanding of the work as a whole, or the artist's mind. In this manner, too, one is able to more accurately express the nature of the piece of art to an audience while still allowing for their own individual interpretations of the work.
Bibliography

Barnett, S. A Short Guide to Writing About Art. New York: Longman, 2003.

Sylvia Barnett, A Short Guide to Writing About Art. (New York: Longman, 2003), 95.

Barnet, Guide, 98.