So, after 4 years in an classics program and 3 years reading at least 1,000 academic papers, I have a few formed thoughts on what makes music good.

Disclaimer: These thoughts come straight from Plato. If you haven't read him, you'll feel like you have after the following crash course in a few of his basic philosophies. And if you stick with me til the end, I promise a sweet "philosophy of music" payoff -- to which I'd love your input.

First, Plato believed the human soul to be comprised of three faculties: the rational, the appetitive, and the spirited. The rational is, you guessed it, given to reason. The appetitive is, guessed right again, given to appetite or desire. And the spirited is, less obviously, the one that mediates between the other two.

Note: By "appetite," Plato didn't mean foodstuffs. He meant "base pleasures," or pleasures controlled by carnal desires devoid of reason.

The one that usually confuses people is the spirited faculty. What does it mean for part of our soul to "mediate" between desire and reason? It might be easier to think of it this way: Whenever our reason and appetite conflict, the spirited faculty is the one that chooses which one to follow. In fact, it's the one that chooses anything that needs choosing, since it's the part of our soul that controls our will.

Plato then says that the goal of a well-lived life is to develop a "just soul," or justice among the three parts. And since reason is what separates us from the animals, justice for the human soul means getting our spirited faculty to defer to our rational faculty instead of our appetitive one. Furthermore, it means getting our appetitive faculty to conform -- even submit -- to reason so that the soul runs smoothly within itself, rather than in combat mode.

With me still? Here's a quick recap:

Man = Reason + Desire + Will
Animals = Desire + Will
Plants, Pianos, Desks, and other Inanimate Objects = None of the Above

Thus, by virtue of our humanness, we should prefer to live in accordance with reason instead of appetite, as choosing the latter likens us unto mere brutes . . . and that can't possibly be good.

Now for the musical connection.

Just as the soul is made of three parts, so is music comprised of three parts: words, rhythms, and modes. And, lo and behold, the three parts of music correspond evenly to the three parts of the soul!

How so?

Well, the words are the "rational" part of music. They communicate the meaning, or idea, of it. (Which, in the case of wordless music, still holds true because it means the main idea motivating the creation of that piece.) Conversely, the rhythm of a piece of music is its "appetitive" part, the part that gets our shoulders moving, our feet tapping, our fingers snapping. In other words, rhythm, like the appetitive portion of our soul, taps into the more visceral parts of our nature. And finally, the mode, or "spirited" part, is what unites the two and gives them life. It's what actualizes the words and rhythms into a piece of music through the power of tone, melody, harmony, time signature, tempo, and/or emotive release.

Now, to apply Plato's idea of the just soul to music, we can create a filter for "good music."

Good music should:

1) Have a motivating idea or purpose, always communicated through words when available.

2) Be supported, not overpowered, by the rhythmic aspect.

3) Fuse words and rhythms through modal choices so as to evoke the power of the main idea in the listener.

4) Carry a resonant "sound," or energy, that uses the instruments, harmonies, melodies, and toe-tapping rhythm to perfectly reflect its main idea.

5) When done well, the discovery of the main idea and its corresponding emotion will be an unavoidable byproduct of listening to the piece.

Some concluding thoughts:

Are we commonly aware of music's power to shape -- and even reflect -- the state of our souls? Do we care that it holds that power? Why or why not?

As someone who cares about the formation of her soul, this goes a long way in explaining why cars that bump and vibrate next to me at the stop light affect me on a physical, even soul-shaking, level. Such an encounter drives me to bodily itchiness, discomfort, and aggravation! And, according to Plato's filter, this must be because I'm actively seeking to be mastered by reason, not appetite, and appetite is just what enslaves that kind of music.

Lord, help us strive to be creatures moved by what is truly good -- which, in the context of music, is that music that carries beautiful ideas and is coupled by corresponding tonalities and rhythms that elevate the spheres of our souls into the heavens, nearer to You. Amen.