Here is a quick summary of what the Venari said. I remember summarizing it for a friend.
- The music itself (not just the lyrics) has an effect on the soul. The ancients (e.g., Confucius, Plato, Aristotle, etc.) all agreed on this: persistent listening to a certain form of music disposes one's soul to virtue or vice.
- There are three possible constituents of music: 1) melody, 2) harmony, and 3) rhythm.
- Each constituent of music stimulates a certain faculty of the human person: 1) melody - intellect, 2) harmony - emotion, and 3) rhythm - passion. Various examples are given to demonstrate this.
- Just as the human person's faculties have a hierarchical order, so must good (i.e., virtuous) music have order.
- The human person's intellect is ordered to a primacy: governance. The emotional appetite of the human person must be guided by reason (the intellect). Likewise, and even more importantly, the passionate appetite must be subordinated to reason (the intellect). Ana logously, good and virtuous music ought to be primarily "governed" by melody (intellect), maybe enhanced by harmony (emotion), and only supported by rhythm (passion).
- Bad music is inversely ordered (i.e., primarily rooted in rhythm and a de-emphasized melody). Examples are heavy metal, rap, techno, etc.