This whole discussion is quite interesting to me. I love music theory in composition, and if I could do anything I wanted for a living it’d be to write music.

The truth of the matter is that music is an intersection between math* and art. You CAN analyze the math part and based on people’s predispositions have a good idea of how they will react to a song. In fact, a person knowing music theory intimately can read a piece of music (even if he or she doesn’t posses the ability to “hear” it in his or her head) and be impressed or bored, if only on the logical level. This part of music could very easily be analyzed in this manner and you could do a decent job of picking out good tunes. However, you might not hit the great ones. Nevertheless, the math part is essential and all musicians must adhere to it. Some musicians have been trained and have learned the rules; other’s just have good ears and have learned the rules by practice, but all good musicians have some feel for them.

The second part- what I consider the “art”- is the intuitive prerogative of the creator. While a good musician must know the mathematical rules (or at the very least follow them intuitively), there is a step beyond the math that is quite immeasurable. If a musician doesn’t know or follow the rules, however, most often the music comes out as either un-listenable or uninteresting. Often artist have to break the rules, but in these cases they generally know exactly what they are doing. A theory professor once likened this to circus performers who ride unicycles. They wobble all over the place like they have no idea how to ride, but the reality is they could never do it if they didn’t know the “correct” way to ride in the first place. Is their knowledge of how to “break” the rules just right that makes it interesting.

To carry the analogy further, an evaluation program like the one linked would promote everyone following the “rules.” That might be a good starting point, but if no one ever gets outside of the box and into the “art” area of music, all we’ll have is a bunch of people riding unicycles very properly around a tent. Not very interesting in the end, is it?

*I say “math” because underlying all music is a system of numbers, and not a simple one either.